OBJECTIVE: To assess the magnitude of clinical inertia and its associated factors among adult patients with asthma on chronic follow-up at Jimma Medical Center, Ethiopia, from December 2021 to May 2022. DESIGN AND SETTING: A hospital-based prospective observational study was conducted in Jimma Medical Center from 1 December 2021 to 30 May 2022. PARTICIPANTS: 135 patients with asthma who fulfilled the inclusion criteria were enrolled in the study consecutively and followed for 3 months. RESULTS: Of 148 patients, 135 patients' data were analysed. The mean (SD) age of the patients was 52.03 (±15.75) years. More than half (54.1%) of the study participants were men. Most of the study participants (68.9%) at the first and (70.4%) at the second visit, which is 3 months after the first visit, had clinical inertia, respectively. Comorbidity (adjusted OR (AOR) 3.35, 95% CI (1.15, 9.81), p<
0.027), asthma duration of 5-10 years (AOR 7.58, 95% CI (1.51, 38.05), p<
0.014), moderate persistent asthma (AOR 6.91, 95% CI (2.46, 19.42), p<
0.00) and severe persistent asthma (AOR 10.84, 95% CI (1.1, 107.0), p<
0.041) were contributing factors for clinical inertia. CONCLUSIONS: The burden of clinical inertia in this study was high at both visits. Comorbidity, duration of asthma of 5-10 years, moderate persistent and severe persistent asthma were identified as contributing factors to clinical inertia. Policymaker intervention to avoid clinical inertia is necessary to improve asthma treatment outcomes.