A series of N-acyl aryl hydrazones (1a-10a) were synthesized by refluxing 2-naphthaldehyde with various substituted cyanoacetohydrazones (1-10). The substituted cyanoacetohydrazones were prepared by treating various substituted aromatic aldehydes with cyanoacetohydrazide. The chemical structures of synthesized compounds were confirmed on the basis of their spectral data. The synthesized compounds were evaluated for antimicrobial activity against bacterial strains Staphylococcus aureus (gram positive), Escherichia coli (gram negative) and fungal strains Penicillium chrysogenum, Penicillium notatum and Aspergillus niger by diffusion assay method. The compounds were also evaluated for anthelminthic activity using earthworms (Pheretima posthuma). Among the derivatives 4-cinnamyl (7a) and 4-pyridyl (8a) showed good potent antimicrobial and antihelminthic activities when compared against their standard drugs oxytetracycline, fluconazole and albendazole respectively.