In order to develop new anti-Helicobacter pylori agents, a series of N1-substituted 3, 5- diphenyl pyrazolines P1–P13 was prepared and evaluated for their antibacterial activity. All synthesized compounds showed little or no activity against different species of Gram- positive and Gram-negative bacteria of clinical relevance and against various strains of pathogenic fungi. The same derivatives exhibited a significant degree of activity against a ...