The uses of plant growth regulators have emerged as an important tool in improving agricultural production. The study was conducted to compare the effects of three PGRs on the yield parameters and sennoside (a and b) contents from leaves and pods of medicinal plant Cassia angustifolia.The PGRs viz., Gibberellic acid (GA3), Indole acetic acid (IAA) and the growth retardant Abscisic acid (ABA) were applied at the concentrations of 25, 50 and 100mg/l as foliar spray. Performances of different PGRs in C. angustifolia indicated that all the PGRs used have caused statistically significant increase in yield attributes and sennoside contents over control. Amongst the different treatments of PGRs, IAA and ABA (100mg/l) had shown maximum positive influence on yield parameters in C angustifolia. While for enhancing sennoside a and b contents from leaves and pods, IAA and ABA (50mg/l) emerged best treatments over control.