Petunia is an important and beautiful ornamental flowering plant, grown throughout the world for its beauty and attraction. Different Petunia hybrids have been developed by petunia growing countries of the world. The prescribed study was conducted to investigate the association of abscisic acid with seed yield and its contributing traits of petunia line. Data for different physiological, morphological and petunia seed yield traits was recorded, analyzed and interpreted for final inferences. From results it was showed that the petunia lines IAGS-P8, IAGS-P9 and IAGS-P11 performed well for most of the studied traits. It was shown from multivariate analysis techniques that stomata conductance, chlorophyll b contents, seed area, chlorophyll a contents, flower fresh mass, flowers per plant, seed mass and abscisic acid contributed higher to seed yield per plant in petunia. The abscisic acid contents showed positive and significant association and contribution towards seed yield of petunia genotypes. It was suggested that selection on the basis of abscisic acid may be useful to develop good seed yield per plant and large number of flowers per plant in petunia under stressful environmental conditions.