Parsnip (Pastinaca sativa L.) is an edible root that has long been used in cooking and preparing baby food and livestock. The present study was performed to evaluate the phenotypic diversity of 69 accessions of this species to select superiors in terms of root quality in Paykan village, Isfahan province, Iran, in the year 2022. There were significant differences among the accessions investigated (ANOVA, p < .01). Coefficient of variation (CV) was more than 20.00% in the majority of measured characters (64 out of 66 characters), indicating high diversity among the accessions. Foliage width (crown) ranged from 10 to 55 cm with an average of 32.32 cm. Root shape was tapering (33), obtriangular (10), narrow oblong (5), wide oblong (5), obovate (13), and fusiform (3). Root length ranged from 81.2 to 294 mm with an average of 166.44 mm. Root diameter at its middle point ranged from 15.58 to 125.12 mm with an average of 51.83 mm. Root weight ranged from 15 to 1200 g with an average of 315.36 g. Inner core (xylem) pigmentation/color was cream yellow (11 accessions), light yellow (12), yellow (42), dark yellow (2), and yellow–light orange (2). In the cluster analysis based on Ward's method, the accessions were divided into two main clusters according to morphological traits. This is despite the fact that parsnip is part of the medicinal plant native and valuable in most farms in tropical cities. Compared with carrots, parsnip plants are more adaptable to different environmental conditions. The accessions studied here showed high phenotypic diversity. Based on ideal values of the important and commercial characters of parsnip, such as root length, root weight, inner core (xylem) pigmentation/color, root shape, flesh color intensity, flesh palatability, and total soluble solids, 14 genotypes, including Parsnip‐3, Parsnip‐9, Parsnip‐24, Parsnip‐32, Parsnip‐32, Parsnip‐48, Parsnip‐51, Parsnip‐52, Parsnip‐58, Parsnip‐60, Parsnip‐62, Parsnip‐65, Parsnip‐67, and Parsnip‐69, were promising and are recommended for cultivation.