The effect of oil and oil products on the 5 species of crustaceans in the Caspian sea was investigated. Two species of shrimp (Palaemon elegans, P. adspersus), crab (Thithropanopeus harrisii tridentatus), amphipoda (Pontogammarus maeoticus), and cirripeda crayfish (Balanus improvisus) are classified among them. Various oil products (oil, phenol, fuel oil, xerosene, gasoline, solar oil) were used in the experiments. The influence of oil on the respiration and mass increase, quality of generation, and larval stages of the crustaceans was studied. Minimal critical concentrations for the crustaceans are 0.001 mg L−1 of fenol, 0.4 mg L−1 of oil, 0.1 mg L−1 of solar oil, 0.01 mg L−1 of gasoline and fuel oil.