Yes. Check out the equipment section.
From the SRD:
"Strike, Unarmed: A Medium-size character deals 1d3 points of subdual damage with an unarmed strike, which may be a punch, kick, head butt, or other type of attack. A Small character deals 1d2 points of subdual damage. The damage from an unarmed strike is considered weapon damage for the purposes of effects that provide a bonus to weapon damage.
Use the Weapon Finesse feat to apply a character's Dexterity modifier instead of the Strength modifier to attack rolls with an unarmed strike."
Hope that helps,
Greg