Abstract: Using α-bungarotoxin (α -Bgtx) and β -bungarotoxin (β -Bgtx) to capture their corresponding proteins from preparation of crude human muscle receptor (triton extract), antibodies against these corresponding proteins were detected in Myasthenia gravis patients. α-Bgtx binds to AChR and β -Bgtx binds to presynaptic membrane receptor (PsmR) of triton extract. The captured proteins were used as antigen in indirect ELISA to detect the IgG antibodies against AChR and PsmR in sera from 146 Indian patients with MG and in 30 controls. Out of 146, 130 were generalised myasthenic patients (GM), 16 ocular Myasthenic patients (OMG). In addition to AChR antibodies, Myasthenia Gravis (MG) patients were also showing antibodies against PsmR. The frequency of anti-AChR antibodies was 71% and anti-PsmR antibodies was 65%. The OD values of GMG for AChR and PsmR were (0.76 ± 0.34) and (0.75 ±0.37), for OMG patients (0.32 ± 0.1) and (0.72 ± 0.42) and for healthy controls (0.16 ±0.06) and (0.18 ±0.04), respectively. These results showed that MG is not only due to the damage of the postsynaptic membrane, but it could concurrently be a consequence of antibody mediated damage of the presynaptic membrane, resulting particularly the damage of its β-Bgtx binding sites and could play an important role in the pathogenesis of MG. Therefore, it is also necessary to detect antibodies against PsmR in addition to AChR antibody.