The present study was conducted to evaluate the effect of Cochlospermum religiosum (CSR) in animal models of depression and anxiety. The CSR leaves are well known for their sedative, antibacterial, antifungal antioxidant, memory enhancing, anxiolytic and antidepressant potential. In present study, the extract of the leaves is used to relieve the anxiolytic and antidepressant potential. The leaves of CSR were investigated for antidepressant and anxiolytic activities in mice behavioural models namely, spontaneous locomotor activity (SLA), forced swim test (FST), tail suspension test (TST), elevated plus maze (EPM) and marble burying behaviour (MBB). The mechanism was supported by reserpine-induced hypothermia (RIH). Further, the in vivo synergistic evaluation of the CSR leaf extract was evaluated with imipramine and fluoxetine. The treatment of mice with ethanolic extract of CSR leaves for 7 days resulted significant antidepressant and anxiolytic effects (p < 0.05 for 50 mg/Kg p.o / p < 0.01 for 100 mg/kg p.o) with null impact on baseline locomotor activity. Further, the study on rat RIH model revealed that the CSR (50 mg/kg p.o) predominantly antagonized the effect (p < 0.05) of reserpine. Furthermore, synergic action was screened by co-administration of leaf extracts of CSR with fluoxetine (10 mg/Kg, i.p.) and imipramine (10 mg/Kg, i.p.) at below therapeutic dose levels using FST, TST, EPM and MBB. The synergistic effect was significant (p < 0.05) for both antidepressant and anxiolytic activities as compared to therapeutic doses of extract, imipramine and fluoxetine.