Objectives In this study, the synthesis of three pyrazoline derivatives and the evaluation of their inhibitory effects on dipeptidyl peptidase (DPP-4) were aimed. Materials and methods Pyrazoline-based compounds (1-3) were obtained via the reaction of 1-(2-furyl)-3-(1,3-benzodioxol-5-yl)-2-propen-1-one with 4-substituted phenylhydrazine hydrochloride. The DPP-4 inhibitory effects of compounds 1-3 were determined with a fluorometric assay using Gly-Pro-Aminomethylcoumarin as the fluorogenic substrate. The cytotoxicity of compounds 1-3 on L929 mouse fibroblast (healthy) cell line was evaluated using MTT assay. Results 1-(4-Methylsulfonylphenyl)-3-(2-furyl)-5-(1,3-benzodioxol-5-yl)-2-pyrazoline (2) exhibited the highest DPP-4 inhibitory activity (IC50=5.75 +/- 0.35 mu M). Moreover, compound 2 exerted no significant cytotoxicity against L929 cells (IC50=34.33 +/- 7.09 mu M). Conclusions Target compounds exhibited moderate DPP-4 inhibitory activity and compound 2 was identified as the most active compound.