I think it'd be either what many people are saying, pupils getting hurt, or Hogwarts shutting down and him not being able to teach. I mean, he absolutely adores teaching; he's said it himself.

i think his fear is if his students get harmed

i don't know!! it can be like u write, but still--> what can Dumbledore be afraid off, on the end he is the most powerful good wizard and he is the only that Voldermolt is afraid off!! Really i wouldn't know :
)

Yeah I agree that his Boggart could be something like how Mrs. Weasley saw everyone dead....DD is afraid that a mistake made by him will harm his school and students.

I totally agree... He definetly has a fear of failing especially if it has something to do with his students or maybe since voldemort set it up was he seeing voldemort killing harry? (total guess) Lets hope we get some explanation of what the potion did to Dumbledore and his boggart in the 7th book!

I think Dumbeldore's boggart was the dark mark in hogwarts's sky and DE's attack to hogwarts and killing students.
if you read chapter the cave again, when dumbledore is drinking that potion you can see all his words will be show to you after his back to hogwarts and see the dakr mark in the sky.
he said: dont kill them, (students) Its my fault ( trusting Snape) and at the end, kill me ( snape kills him at hogwarts)
he was a trusty man and all of his fears was about people who he has trusted them. someone like snape.
all dumbledore words when he is drinking the green potion, figurates in the next chapter.

i think it is that or making a mistake that gets harry killed and voldemort is trying to torture all the people close to him and the students in his care.

his biggest fear is to see Harry dead because all the way in he books he's tried to save Harry not only because of the prophecy but becaus he loves him as a son

I agree completly, he knows that he can not risk Harry being killed since he is the only way of freeing the Wizarding World of Voldemort, so it scairs him to think that he put Harry in a situation that he will be killed.

Yeah i agree, has to be harry getting killed or mcgonagol coz i think he's inlove with her!!!

i think it would be harry dead and voldemort standing on his body

I agree with all the students harm and all that, but maybe its something else. Like maybe, at school, he did something that endangered his fellow students. OR maybe, once he was under the imperius curse and tried to do someone in. OR he saw someone trying to kill someone, and offered his own life in exchange. Weird....

I think his boggart would be the Dark Lord winning the war & taking control over the wizzarding world.

I think Dumblodore's boggart would have been people he cared about dead. Harry among them of course.
I dont know, a boggart usually shows an object , maybe 2. THe picture you described is rather complicated.
Anyway Dumblodore's fears were connected with voldemort though
he wasnt anxious about himself, but others.

It is interesting that JKR never showed us any of Dumblodore's deep emotions: remember she didnt tell us what he saw in the Mirror of Erised in the first book either.. Though it must have been "everyone fine-voldemort gone " image.

I think Dumbledore's Boggert would be something similar to what happened the night he was killed. Not his own death, but the slaughter of Hogwart's students by the likes of Fenrir and the other DE's, Harry included. We know little about his own family other than he has a brother, Aberforth.

"I must not fear. Fear is the mind-killer." Ah, another Dune fan!!!!

I am still convinced that Dumbledore's Boggart is either a Phoenix or a lion (being the Gryffindor symbol I think). But imagine if it was a pygmy puff

I don't think so... a boggart is is a shape-shifter that takes on the form of its intended victim's worst fear.

Why would Dumbledore fear a Phoenix or a lion?

Duh! I was thinking of Patronuses...stupid me!

I think his worst fear is being told that Hogwarts had collapsed

I think his boggart is probably the Wizarding World being tortured by Voldemort.

I went through HBP's "The Cave" chapter and I read all the things Dumbledore said when he was taking the potion.

Here are some of them...

I thought this quote was interesting. It sounds like Dumbledore is talking about something that may have happened in the past. If so, I wonder what it was that he did wrong. Maybe his greatest fear is something horrible that actually happened. Or, maybe his fear is that something horrible that happened to him once will happen again in the future. Or maybe, he's imagining how guilty and horrible he'd feel if something ever did go wrong and it was his fault.

I guess I agree with the idea that Dumbledore's fear is harm coming to others because of something he did. It shows he's really selfish, if he's so concered that he could cause harm to others.

Yes I belive Dumbledore's boggart would be the suffering of other people. He really cares for others before himself.

Do boggarts change? As we progress through life, our greatest fears change, so why not boggarts? I think, throughout his life, his boggart has taken many forms. Since he turned down the MoM job to become headmaster, we have to assume it has something to do with Hogwarts. Harm to students and destruction of Hogwarts are good candidates prior to Harry, but Harry's safety must have become primary when his greatest fear became reality with the return of LV.

Well some people would say that dumbledore fears nothing, but everyone knows that total bolony because he's human. I'd say that his boggart would be the fear of making a mistake. it would make a lot of sense seeing as almost everyone(excluding voldemort's followers) looks up to dumbldore.