DSM-IV Axis I and II comorbidities and the pattern of Axis II diagnoses in patients admitted at Mathari (Psychiatric) Hospital, Nairobi, Kenya are unknown. To determine DSM-IV Axis I and II comorbidities and patterns of Axis II diagnoses in patients admitted at Mathari Hospital. Cross-sectional study on 148 randomly sampled patients. Twenty percent of the patients were confirmed for an Axis II diagnosis. Eighty-seven percent of the Axis II disorders were Cluster B Personality Disorders of various types. Using chi2 tests, significant associations were found between Axis I and II diagnoses and substance use/dependence (p < 0.001; 66.7%), mood disorder (p = 0.002; 46.7%) and schizophrenia (p < 0.001; 23.3%). The prevalence of personality disorders was lower than that reported in psychiatric patients in USA and Europe. The results are likely to be a true reflection of the actual epidemiological situation, but cannot be generalized to outpatient or general populations.