Provided is an electrodepositable coating composition of a resinous phase dispersed in an aqueous medium, the resinous phase including (a) an active hydrogen-containing, cationic salt group-containing resin; and (b) an at least partially blocked polyisocyanate curing agent. The composition contains an organotin catalyst which is or is derived from a dialkyltin compound having the structure (I): [R.sub.1][R.sub.2]--Sn.dbd.O (I) where R.sub.1 and R.sub.2 are the same or different, and each independently represents a monovalent hydrocarbon group wherein the sum of the carbon atoms in R.sub.1 and R.sub.2 is greater than 8. The catalyst is present in an amount sufficient to effect cure at a temperature at or below 340.degree. F. (171.1.degree. C.). Methods of preparing and using the composition also are provided.