In this study, the rate of copper accumulation in mussel (Mytilus galloprovincialis) and sea snail (Rapana venosa) organisms exposed to acutely different non-lethal copper concentrations was investigated for 5 days under laboratory conditions. All soft tissue concentrations were analyzed using an Inductively Coupled Plasma Optical Emission Spectrophotometer. At the end of accumulation, the rate of increase of copper level in mussel and snail soft tissues in different aquariums was found to be 19.19-36.93 and 2.37-7.41 times higher for mussel and snail soft tissues than before exposure, respectively. Differences in metal accumulation at the end of the experiment between species were not statistically significant (p > 0.05). In addition, bio-concentration factor and rates of accumulation values were calculated for both organisms. The corresponding bio-concentration factor values for mussels after exposure to 0.12, 0.36, and 0.60 mg L-1 copper were 406.00, 168.41, and 165.16, respectively, while the corresponding bio-concentration factor values for snails after exposure to 0.12, 0.36, and 0.60 mg L-1 copper were 276.29, 272.12, and 265.73, respectively. While accumulation rate values were 10.15, 12.26, and 20.12 for mussels exposed to 0.12, 0.36, and 0.60 mg L-1 copper, respectively, accumulation rate values were 6.85, 19.76, and 31.69 for snails exposed to 0.12, 0.36, and 0.60 mg L-1 copper, respectively.