This research aims to discover the effects of different pressure shocks, heat shocks and times after fertilization on the formation of tetraploid rainbow trout at the stages of eyed eggs, yolk-sac larvae, feed started fry. This research was designed using factorial completely randomized design consisting of three main treatments i.e. pressure shock as 9000 and 10000 psi, heat shock as 26.5oC and 30.5oC, time after fertilization as 300, 315 and 330 minutes. The shock duration for all treatments was 3 minutes. The survival rates of control groups were higher than the results of all other groups and significantly different. The highest survival rate in feed started fry was observed as 80.72% (9000 psi, 315 min). The following best results were obtained as 78.84% (10000 psi, 315 min), 75.57% (26.5oC, 300 min), 65.38% (30.5oC, 330 min). It is possible to conclude from these results that high pressure and heat shock levels and long time after fertilization caused to the reduction in survival rates. When maximum and minimum survival rates obtained in pressure and heat shock applications were compared, it was observed as maximum 80.72% and minimum 70.76% in pressure shock applications and maximum 75.57% and minimum 61.02% in heat shock applications. It is possible to interpret by acting from these figures that pressure shock treatments led to better results than heat shock treatments