In order to compare planting season effect on agronomic of characters and yield of dill (Anethum graveolens L.) an experiment based on completely randomized design with three replications was conducted in 2006-07 in Esfahan province and three planting seasons (spring, summer and autumn) were evaluated. Essential oil compositions were obtained by Clevenger and recognized by GC-Mass and GC. According to results, the majority of seedlings were injured in autumn planting date (November) and effect of planting seasons on fresh and dry biological yields and essential oil of foliage were significant. In spring (March) and summer (June), fresh and dry biological yields were 5.4, 1.1 kg/m2 and 3.7, 0.8 kg/m2, respectively. Essential oil quantity was also 10.2 and 5.3 cc/m2, respectively. The most important components in essence were carvon with 58.5 and 52.2% in spring and summer seasons, respectively. Thus, cultivation of dill in spring and summer seasons in order to produce seed, foliage and essential oil was successful.