Silver nanoparticles (AgNPs) synthesized using numerous types of coating materials may exhibit different toxicity effects. The study evaluated coating material dependent toxicity by selecting 3 types of AgNP synthesis methods with different coating materials (citrate, polyvinyl pyrrolidone, and branched polyethyleneimine, coated AgNPs as citrate-AgNPs, PVP-AgNPs, and BPEI-AgNPs respectively). Two acute aquatic toxicity tests were performed; 48hr D. magna and MetPLATE E. coli toxicity tests. Significantly different toxicity effects were observed in D. magna test exhibiting lethal median concentrations (LC50) for citrate-AgNPs, PVP-AgNPs, and BPEI AgNPs respectively as, 2.7, 11.2, and 0.57μg/L. Median inhibitory concentrations (EC50) for MetPLATE tests were 1.27, 1.73, and 0.31mg/L respectively with significant different toxicity effects. Silver ion fractions were detected in the range of 2.4-19.2% in tested NP suspensions. Study suggests the toxicity effects are due to the cumulative action of ionic and nanoparticle fractions in the suspensions.