Do I need to repot my lucky bamboo?

Well first of all don't repot if you are in the northern hemisphere. Plants don't like to be repotted in the winter. If it was seriously root-bound and dying you might want to as a last resort but it's best to wait for spring. It's producing leaves so it seems to be healthy. They are small - again, it's winter. More sunlight in the summer = bigger leaves. Given that, you may not not need to repot at all. Some plants like to be root bound. Do some research on your particular species of bamboo (there are many) so you can make better choices for it's care. Don't be tempted to drop fertilizer in it either. Chemical fertilizers are often death to potted plants (chemical salt build up) particularly in winter when they can't use them.

Lucky Bamboo is not a bamboo, but a Dracaena sanderiana...... http://houseplants.about.com/od/typesofhouseplants/a/LuckyBamboo.htm if it is potted in soil, wait till spring is full on.....for now, with all the new growth occurring, do the 'drop of fertilizer' thing if in water, and regular fertilizing if in soil.....just a little for now... less is always better than too much.....

Edging twice a year is best, both for the health of the bamboo and to keep it fully under control. Edging involves cutting back the rhizomes as they expand to the edge of the designated growing area.