Egg production rates (EPRs) of Calanus euxinus were measured in the Black Sea during October 2000 and May 2001. EPRs were generally low, on average 1.7 eggs female(-1) day(-1) in October 2000 and 3.9 eggs female(-1) day(-1) in May 2001. The relationships between EPRs and gonad maturity, depth-integrated chlorophyll a (Chl a) and mean surface layer temperature were examined. The EPRs were not related to depth-integrated Chl a, but were negatively correlated with temperature. EPRs were strongly related to the proportion of mature females. Growth rates of C. euxinus were derived from the EPRs. The mean growth rate was 0.011 day(-1) in October 2000 and 0.03 day(-1) in May 2001. Growth rates were not significantly correlated with Chl a concentrations, but were negatively related to female weight and temperature.