This study was conducted to investigate the effect of pollen source on the quantitative and qualitative characteristics of the Piarom cultivar. Five treatments, including male date palms (cvs. Spake, Meskotan, Fanoj, Grambit, and Zaboli), were used on twenty 15-year-old cv. Piarom date palm trees in a complete randomized block design with four replications in one of the commercial orchards in Bampour city during 2021-2022. The physical properties of the fruit were measured, which included time of fruit ripening, fruit set, parthenocarpic fruits, fruit drop, the length and diameter of the fruit, the volume of the fruit, the length and diameter of the seeds, the weight of the seeds, the weight of pulp, the fruits bunch-1 weight, the weight of parthenocarpic fruits, bunch weight and the yield. The results showed that the pollen grains had significant differences in fruit formation, fruit drop, fruit length, diameter, weight and volume, seed length and diameter, bunch weight, fruit flesh weight, soluble solids content and yield. Among the male parent pollens, Fanoj and Zaboli had the highest fruit formation (57.24 and 57.15 %, respectively) and the lowest fruit drop (34.33, and 33.63%, respectively), whereas Grambit had the highest fruit weight, volume, length and diameter. Cvs. Zaboli and Fanoj also had the highest bunch weight. Moreover, the yield per tree using cvs. Zaboli and Fanoj male parent pollens was 64.1 and 62.5 kg, respectively. Based on the results of this study, the use of cvs. Zaboli and Fanoj male parent pollen for the pollination of the cv. Piarom is recommended to increase the percentage of fruit formation, bunch weight and yield as well.