Illegal alcohol beverages known as bogma raki in our country are consumed widely in our region. The studies investigating the relationship between alcohol consumption and hearing ability report different results. In this study, we aimed to investigate the toxic effects of bogma raki that contains neurotoxic substances on cochlea by electron microscopy. To the best of our knowledge, this study is the first in the literature. A total of 48 Wistar male albino rats (aged 12–16 weeks and weighing 200–240 g) were used in the study. The rats were divided into 4 groups with 12 animals in each group. The groups include control, bogma raki, walnut, and walnut + bogma raki groups. Bogma raki (30% v/v, 9.2 ml kg−1 day−1) is added to drinking water of rats in bogma raki group (n = 12) for 4 weeks. Walnut group rats (n = 12) are fed with standard rat food and walnut without limitation (10 g kg−1 day−1). Bogma raki + walnut group rats (n = 12) are fed with standard rat food and walnut and bogma raki is added to drinking water. The cochleas were dissected and removed en bloc and examined by electron microscopy. Perineuronal oedema around neurons of spiral ganglion and hairy cells of organ of Corti were present in the bogma raki group, walnut group and bogma raki + walnut group under electron microscopic examination. Comparing these three groups, there were no differences in the ultrastructural pathological changes. In the ultrastructural examination of the myelinated axons forming cochlear nerve, no ultrastructural pathology was detected in all the groups.