Part of a larger study regarding the genetic polymorphisms present in the human population of Romania, we have studied the frequency and transmission of AB0 blood groups in Roman, Neamţ County. We have investigated a population of school-boys from Roman town, Neamţ County. The blood groups frequency were: 0 = 30%; A = 42%; B = 19%; AB = 9%. These values are in accordance with the values registered for all Romanian population. In Roman town, between 2001-2004, the frequency of blood groups is, also, in accordance with our results. The blood groups 0, B and AB are more frequent in males, and A is more frequent in females. It is, on the other hand, difficult to compare our results with the worldwide situation.