A group of 3,5-diaryl-2-pyrazoline derivatives were prepared via the reaction of various chalcones with hydrazine hydrate in ethanol. A group of NO-donating-2-pyrazoline derivatives were synthesized by carrying a nitrate ester group or an oxime group onto the prepared pyrazoline derivatives through different spacers. The prepared compounds were evaluated for their anti-inflammatory activity using carrageenan-induced rat paw edema and compared to a well-known NSAID, indomethacin as a reference drug. The ability of the prepared compounds to induce gastric toxicity was also evaluated. Most of the prepared compounds showed significant anti-inflammatory activity at the injected dose (100mg/kg) but they were safer than indomethacin in regard to gastric toxicity. The incorporation of the NO-donating group into the parent pyrazoline derivatives caused a non-significant reduction in the anti-inflammatory activity while a marked decrease in gastric ulcerations induced by their parent pyrazolines was observed.