In this study, age, length and weight distributions together with density and biomass of fish species in the studied section for 16 km of the Kadıncık Brook which is one of the important tributaries of the Tarsus Stream were researched. In addition to these, distribution area of brown trout in the brook was also investigated. In the studied section of Kadıncık Brook, were two species caught to be brown trout (Salmo trutta macrostigma Dumeril, 1858) and rainbow trout (Oncorhynchus mykiss Walbaum, 1792) in the period of September 9-18, 2002. First brown trout was caught at 8.6th km of the Kadıncık Brook. It was observed that fish quantity increased from that point towards headwater. Sixty-four nos. brown trout and 15 nos. rainbow trout caught from the Kadıncık Brook were determined to be consist of five age-groups and two age-groups, respectively. To estimate density and biomass, the studied section of Kadıncık Brook according to nature of bottom and habitat was separated into four strata. Thirty-six sampling sites at length for 200 m in these strata were selected and in the selected sections, carried out single catch by electrofishing. Removal method based on single-pass electrofishing was carried out to obtained data. Density and biomass were estimated as 28 inds. $ha^{-1}$ and 2,55 kg $ha^{-1}$ for brown trout and 3,47 inds. $ha^{-1}$ and 1,56 kg $ha^{-1}$ for rainbow trout, respectively. Density and biomass of fish in Kadıncık Brook were estimated as 32 inds. $ha^{-1}$ and 4,1 kg $ha^{-1}$ , respectively.