Abstract: In this study, the relationship between spermatozoa motility, egg size, fecundity and fertilization rates were investigated. Sperm and eggs were collected without anesthesia by abdominal massage from brown trout (Salmo trutta fario). Fertilization rates ranged from 35 to 72% and correlated positively with spermatozoa motility (r = 0.333, p>0.05) and egg size (r = 0.749, p<0.05). On the other hand, negative correlation (r = -0.393, p>0.05) was evaluated between fertilization rates and fecundity. Consequently it was determined that increase in spermatozoa motility and egg sizes effect the fertilization success positively in brown trout.