Authors studies impedance, stapedius reflex thresholds and stapedius muscle exhaustion on 31 ears of 16 MG patients. Investigations were carried out using GSI 33 computer-assisted middle ear analyzator. Stapedius reflex threshold values were increased in 93% of patients. Stapedius exhaustion was observed in 71% of patients. After the administration of the reversible cholinesterase inhibitor Mestinon (60 mg pyridostigmin bromide), reflex threshold decreased and exhaustion occurred in only 50% of cases. Authors review the literature in context with the audiometric diagnostics of MG and also recommend the use of these methods in more complicated ocular and bulbar cases of MG.