SummaryIn our effort to give some information which investigates autecological parameters for southern barbel, a study of age, growth and reproduction for this species was carried out in the Rentina stream, northeastern Greece. The length‐weight relationship can be described by the equations W = 0.008 L3.159and W = 0.0583 L2.428for females and males, respectively (W = body weight in g, L = fork length in cm). The most rapid growth in length occured during the first year of life (7.3 cm) after which growth decreased and remained constant at approximately 3.4 cm per year. The average density and biomass were 0.25 fish. m‐2and 9.35 g. m‐2, respectively. The southern barbel becomes sexualy mature at the second year of life for both sexes. The mean absolute fecundity was 9119 ± 322 eggs with mean diameter 1.2 ± 0.2 mm. Spawning of this species, in the study area, occurs in June at mean temperatu