Cases of dubious paternity may be resolved analyzing appropriate genetic markers in them.To report the experience of a Colombian University in resolving cases of dubious paternity.Fourteen serologic and electrophoretic genetic markers, that had a high probability of exclusion were analyzed in 349 cases of uncertain paternity.In 50 cases, paternity was excluded and in 34, paternity was attributed with a probability over 0.99. In 85 cases, the paternity index was between 19 and 100, that classifies paternity as probable and in 179 cases, the analysis was inconclusive.These genetic markers may be useful in the first approach to a paternity in investigation.