In this study, the effects of a porphyrazine derivative, [octakis (2-trimethylammoniumethyl thio) porphy-razinatocobalt] octaiodide (CoPzq), were explored on the developmental characteristics, sex ratio and egg fertility of Drosophila melanogaster. CoPzq was preferred in the study due to its probability to be used as a chemotherapeutic agent in medicine. As a result of the application of CoPzq, a phenotypic abnormality was revealed within the individuals of F(1) and F(2) generation of Drosophila. Although individuals of F(2) generation did not directly come into contact with the chemical, the rate of abnormality is high. An increase was observed within both generations in terms of the egg fertility. Besides, a deviation emerged in the sex-ratio in some concentrations.