Worldwide, an estimated 5.8 trillion cigarettes are smoked daily and with the growing global smoking epidemic, the environmental burden of cigarette litter will likely intensify. With more than 600 ingredients in a cigarette and thousands of chemicals in cigarette smoke, the world’s aquatic environments may be at the greatest risk for cigarette litters’ effects. The main aim of this study is to gain a further understanding of the bioaccumulation of heavy metals (As, Cd, Cr, Cu, Ni, Pb, Se, and Zn) of cigarette litter origin in freshwater fish and marine mussels. Using fish and shellfish bioassays, the bioaccumulation of these metals was determined in fish feeding (cigarette litter incorporated into fish food) and cigarette litter leachate tests. In the litter feeding study, rainbow trout (Oncorhynchus mykiss) were fed food with a 0.25 and 0.50 pulverized cigarette litter to Trout Chow ratios for 28 days, and, in comparison to the controls, bioaccumulation of metals was not found to be statistically significant at the p ≥ 0.05 significance level. In one cigarette leachate study, rainbow trout were exposed for 28 days to leachate with a concentration of 0.50 cigarette/L (c/L), and compared to the control, bioaccumulation of metals was not found to be statistically significant (p ≥ 0.05). In a separate cigarette leachate study, the Mediterranean mussel (Mytilus galloprovincialis ) was exposed to leachate for 28 days at a leachate concentration of 1.0 c/L. Bioaccumulation of metals was not found to be statistically significant (p ≥ 0.05). Until the present study, the bioaccumulation potential of metals of cigarette litter origin had never been assessed in aquatic organisms. The reasons for a lack of significant bioaccumulation in the present study are unknown, but may be due to the fact that the metals were not present in significant levels in the cigarette litter itself. Additionally, leaching capabilities of metals from cigarette butts may be limited and dependent on the leaching conditions. Further research is necessary to indicate the true potential risks of metals in cigarette litter and whether or not they pose detrimental effects to the environment.