Length weight relationship, relative condition, size at first maturity and sex ratio of Indian mackerel Rastrelliger kanagurta was studied based on the data collected from the ring net and trawl net catches landed at Puthiappa in Calicut during the period July 2001 to December 2004.The length weight relationship for the pooled male and female was W = 0.0000014 L^3.38 and that of indeterminate category was W = .000044 L^2.67.The condition factor per length group the highest value was at 145 mm and in the monthly values, the lowest in May in the samples from both ring net and trawl net. Sex ratio showed deviation from'1:l in certain months. The size at first maturity was estimated to be 173 mm for both the sexes.