Based on paralyzed and death time, zinc oxide (ZnO) nanoparticles (NPs) were preliminarily investigated for possible biological effectiveness of anthelmintic activity on Pheretima Posthuma. After synthesizing ZnO NPs by low-temperature precipitation method with slight modification, size, morphology, and shape evaluation of these nanoparticles were characterized by scanning electron microscopy and annealing temperature in the range 400-700C. In this anthelmintic assay, the paralyzed time (PT) was gradually shorter with the increase of the sample concentration, for instance, when high concentration (40mg/ml) sample was applied on adult worms the paralyzed time was 35.6 minutes only. The death time (DT) was 450 and 80 minutes when the sample concentration was 20 and 40 mg/ml respectively. These results were compared with albendazole as a reference showed PT and DT 378.6 and 402.3 minutes respectively, and showed maximum dose-dependent anthelmintic activity. Finally, at higher concentration paralytic effect (PE) was showed much earlier and subsequently, it is important to note that the time taken for death observation was shorter.