Growth characteristics, slaughter yield and proximate composition of rainbow trout reared under commercial condition in Black Sea were investigated for one production season. The fish were weighted and sampled for quality assessment every month during the production period (December-May), and feed consumption was recorded daily. During the experiment, bimonthly body weight increased from 206 g to 1011 g, specific growth rate varied between 0.4 and 4.79, thermal growth coefficient varied between 0.04 and 0.35. Condition factor, visceral index and hepatosomatic index was altered by feed intake and water temperature. The degree of caecal fat score was highest during harvest month, May. Although carcass yield didn't differ significantly during farming period, fillet yield increased in the last three months. Protein content of fillet lowered from 83% to 70% by the production period. The fillet fat content increased from 10-11% to 15-16% during the experiment, and the most pronounced fat increase occurred in May. Fillets partitioned into six chunks: cranial, intermediate, caudal and their ventral, dorsal subdivisions. Results show small differences in the protein, fat and moisture content of these sections.