To study the effects of zinc nanoparticles on date palm cv. Estamaran (Sayer) callus induction under in vitro condition, a research with two separate experiments was conducted using a completely randomized design. In the first experiment, MS basal salt medium containing 100 mg/l 2,4-D, 3 mg/l 2ip, 3 g/l activated charcoal, 30 g/l sucrose, 40 mg/l adenine sulfate, and 1 mg/l biotin along with different concentrations of zinc sulfate (ZnSO4), including 0, 2.43, 4.86 mg/l or zinc oxide nanoparticles (ZnO NPs), including 0, 2.43, 4.86, 7.29 mg/l , were used. While in the second experiment, the effect of various medium strengths including full strength MS, ½ MS, and ¼ MS was examined on callus formation. At the end of each experiment, total explants induced callus, embryogenic callus formation percentage, and callus fresh and dry weight were evaluated. Results of the first experiment showed that the best callus induction and callus fresh and dry weight belong to MS medium containing 2.43 mg/l ZnO NPs. Further, higher ZnO NPs concentrations had negative effects on callus formation. However, results of the second experiment indicated that highest callus formation and callus fresh and dry weight are obtained on full strength MS basal salt medium.