well flower drop is normally due to lack of pollination. Lack of pollination can be due to a number of things.
Weather can be too hot or too cold or too wet. Where are you at? I suggest filling out the location info in your profile, it makes it easier to make suggestions..:)
Could be the plant has its max fruit load at this time and will drop flowers till some peppers are ripe and picked, could be disease, could be pests.
How about some more info and possibly some pics so we can help you better..:)
kendra

I have a chili plant (exact type unknown) that is suffering flower drop. It has been on a sunny window ledge which I'm told can be part of the cause. I read above that it can also be to do with lack of pollination. My plant flowers quite profusely. I was wondering if, once bud drop starts, can it be "fixed"? And if so, can someone suggest what I might try? This is the first time I have tried to grow them indoors. I normally do it outside and have no problems. But we've had a cold wet summer and so haven't tried to put them outside this year. Help?

This is a common problem...

Here is a link that might be useful: Flower drop

minders>>try hand pollinating your flowers to see ifyou get better results. Some people use small paintbrushes to transfer pollen from flower to flower, some people use q-tips, some people glue the flower shut and it pollinates itself.
Myself, I pick one flower that is perfectly open, then i "pollinate" other flowers on the plant with a little flower nookie...:)

kendra

Thanks for that. I didn't realise a plant could pollinate itself. I thought it had to be another plant. I'll have a go at pretending to be a bee when I get to work tomorrow. I've got my chili plant on the window next to my desk. Helps keep my mind off work :o)

I have now bought a mister and have been pollinating my flowers daily... I must look a sight, but I don't care!

One further question... there are a couple of us growing chili plants here in my office. Mine is by far the best looking as I pinched out the growing tip several weeks back and so have lots more growth, however, one girl's plant is infested with aphids which got on mine. I have moved hers to a different window than mine and have been obsessively scanning for an wiping off any aphids that I've found since. However, I feel they will keep coming back, especially with the colony of them on the next window ledge. I've read about ladybirds being a good natural way to get rid of them, but don't now how well it would go down if I released a box of bugs next to my desk! LOL! I've heard of spraying plants with a mild soapy solution. We have "pH neutral washing up liquid" in the kitchen for doing the dishes with. Could I use this to get rid of the aphids without harming the plant? And how weak/strong would I have to make it if it's usable? I seem to recall trying a soap solution once years ago but I think I made it too strong and killed the plant. Oops. Any advice? I will, of course, spray the infested plant too if this is a viable option. Failing that, I will just catch a few ladybirds (ladybugs in the US) from my garden at the weekend and see what they do. I can just deny they came from me if they end up on someone else's desk. >:o)

the ladybugs are the most efficient aphid killers if you have a big population.
you can wipe them off by hand and a strong spray of water can also knock them off and kill them.
you are right, they will keep coming back and probably you need to get everyone in your office on aphid patrol..:)LOL
there is a recipe for soap spray but I don't think you can use just any old soap.
I apologize I dont' know the recipe but I don't grow the plants inside at all because of aphids. Someone here will know or you can do a general search for insecticidal soap spray or soap spray.
Also, there are a few commercial products that will work sometimes on small quantities of aphids such as "garden spray" and "safer spray" that are both insecticides that you can buy in the nursery department of most stores.

kendra

I don't know where you are, but I'm experiencing some problems with fruit set.

I'm puzzled myself because I have two poblanos next to each other. One plant has several pods developing while the other plant [though it looks great] doesn't.

I think it's because I got a late start and the heat is incredible right now here in Florida.

Flower drop probable causes:

1. Day temp too high >95F
2. Night temp too low 3. Too much nitrogen fertilizer
4. Too much water
5. Low light levels (reduces fertility).
6. Very low humidity (reduces fertility)
7. Poor air circulation (air circulation contributes to pollination).
8. Lack of pollinating insects.
9. Size of pot