The present investigation entitled "Genetic studies of seed yield and its attributes in ajwain (Trachyspermum ammi L.)" was carried out by using forty diverse genotypes of ajwain obtained from seed spices research station, SDAU, Jagudan and evaluated in randomized block design (RBD) with three replications at Agronomy instruction farm, Sardarkrushinagar Dantiwada Agricultural University, Dantiwada during rabi 2019-20. It would be reasonable to suggest that a breeder engaged in the improvements of ajwain seed yield per plant should place emphasis on number of branches per plant, number of umbels per plant, number of umbelletes per umbel, number of seeds per umbel. Selection for these traits will be directly helpful in increasing the seed yield.