Objective: To evaluate drug therapy problems in asthma patients visiting a secondary and tertiary hospital in South-Eastern Nigeria.Methods: This study was a retrospective, cross-sectional analyses of the medical records of adult asthmatic patients receiving care in two hospitals in Enugu State, within a 15-year period. The Pharmaceutical Network Care Europe (PCNE) tool version 6.2 was used to assess drug therapy problems. The IBM Statistical Product for Services Solution (SPSS) version 20.0 was used for analysis. For all results, P ≤ 0.05 was considered statistically significant.Results: Majority of the patients were below 60 y old (81.2%); female (68.8%) and were on more than two drugs (95.3%). Majority of the identified drug therapy problems (DTPs) were adverse reactions (65.7%). The inappropriate drug combination was the major cause of DTPs (65.6%). Only about 23.4% of the intervention outcomes were known. University of Nigeria Teaching Hospital (UNTH) had more interventions (35.9%) than Medical Centre (8.0%) (χ2 = 6.323; df = 1; **P = 0.012); and more of the outcomes of their interventions known (38.5%) compared to Medical Centre (0.0%) (χ2 = 12.559; df = 1; **P ˂ 0.001).Conclusion: Adverse reactions and inappropriate drug selection were the major identified DTPs and major cause of DTPs, respectively. Most DTPs had no interventions. The documented interventions included stopping of the drugs, change of drugs or dosage, change of instructions for use and starting of new drugs. Most interventions had unknown outcomes. UNTH had more interventions with known outcomes than the University of Nigeria Medical Centre.