The incidence of cuticular lesions on the ventral abdominal integument of the tsetse Glossina pallidipes, G. Brevipalpis and G. austeni was monitored by trapping over 12 months in four localities along the Kenyan coast. Four types of lesions were observed: necrotic pits, necrotic warts, necrotic striations and necrotic discs. Necrotic discs were most prevalent, and up to 30.5% of female tsetse had this type of lesion. The differences in cuticular lesion levels on flies trapped in the dry and wet seasons were not significant. There were no significant differences in the proportions of tsetse with lesions sampled at different sites. Females had a significantly higher proportion of necrotic pits, necrotic warts and necrotic striations than males but the level of necrotic discs on males and females were the same. Histological examination of tissues did not demonstrate any causal association between lesions and infectious microorganisms. There was no correlation between the presence of cuticular lesions and hypertrophy of the salivary glands, a pathology associated with virus-like particles in G. pallidipes.