The efficacy of antipsychotic medications in the treatment of negative symptoms of schizophrenia is modest at best. Preliminary studies suggest the beneficial effects of add on Yoga, a traditional Indian practice, in the treatment of schizophrenia. Hence, in this study, we examined the efficacy of yoga as an add-on treatment for negative symptoms of schizophrenia in a randomized, wait-list controlled design from two clinical institutes in south India. 89 patients (age - 34.20 ± 8.06 years; education - 14.22 ± 2.69 years; 28 females) were randomized into the add-on yoga or treatment as usual (TAU - wait-list control) group. Patients had a mean illness duration of 10.97 ± 7.24 years with an age at onset of 23.34 ± 5.81 years. Central block randomization was followed to ensure concealed allocation. Participants randomized to the yoga treatment group attended 12 supervised yoga training sessions over two weeks and practiced yoga sessions at home for the subsequent 10 weeks. 64 patients completed the trial. An intent to treat analysis was conducted with 89 participants using a linear mixed model. Improvement in negative symptoms was our primary outcome measure. The two groups were matched on demographic variables and baseline psychopathology severity. Participants in the add-on yoga group had significantly greater improvement in negative symptoms (SANS baseline: 49.13 ± 2.30; 12-weeks follow up: 31.55 ± 2.53) compared to the TAU group (SANS baseline: 51.22 ± 2.40; 12-weeks follow up: 45.30 ± 2.93; t = 3.36; p = 0.006; Cohen's d-0.65). The current study findings suggest the efficacy of yoga as an add-on treatment for negative symptoms of schizophrenia. The effectiveness of yoga practice as a regular clinical intervention for patients needs to be explored in future studies by integrating yoga services along with other clinical services.