This study aimed to define the morphological characters useful to discriminate wild from stocked brown trout Salmo trutta in Serbia. Rainbow trout Oncorhynchus mykiss and Ohrid Lake’s belvica Salmothymus ohridanus were also examined as outgroup taxa in order to understand better the overall variability and to reduce bias in the methodology applied. Certain continuous external morphological characters were found useful to distinguish clearly the wild and stocked brown trout in particular streams. Molecular analysis is needed to validate this result, which could permit rapid field assessment and subsequent conservation of wild or stocked origin of as yet uninvestigated brown trout stocks in Serbia.