This study was carried out to clarify the toxicity properties of Flower-like zinc oxide nanoparticles (ZnO NPs) on collected sperm samples from Cyprinus carpio using computer-assisted sperm analysis (CASA). Flower-like ZnO NPs were successfully synthesized using a simple system at 120 degrees C for 5 h by the microwave-assisted solvothermal techniques. The synthesized ZnO NPs were characterized for its structural, morphological and thermal properties. After that, the different concentrations of synthesized ZnO NPs (0.001, 0.01, 0.1, 0.5, 1 ppm) were examined with Cyprinus carpio sperm samples collected from Karakaya reservoir. The spermatozoa motility parameters which contain to curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), straightness (STR), amplitude of lateral head displacement (ALH), and beat cross frequency (BCF) was computed and recorded by CASA. According to the results, while VCL, VAP and BCF were statistically significant (P<0.05), VSL, ALH and STR were not statistically significant (P>0.05). In addition, the EC50 values of VCL and VAP parameters were calculated 0.56 ppm and 0.004 ppm, respectively.