Objective To determine the magnitude and factors associated with psychotropic drug-induced parkinsonism and akathisia among mentally ill patients. Methods A hospital-based cross-sectional study was conducted with a total of 410 participants attending a follow-up treatment service at Jimma Medical Center, a psychiatry clinic from April to June 2019. Participants were recruited using a systematic random sampling method. Drug-induced parkinsonism and akathisia were assessed using the Extra-pyramidal Symptom Rating Scale. Substance use was assessed using the World Health Organization Alcohol, Smoking, and Substance Involvement Screening Test. Data entry was done using EpiData version 3.1, and analysis done by the Statistical Package for Social Sciences version 22. Statistically, the significant association was declared by adjusted odds ratio, 95% confidence interval, and p-value less than or equal to 0.05. Results The mean age of the respondents was 33.3 years (SD ± 8.55). Most of the participants 223 (54.4%) had a diagnosis of schizophrenia. The prevalence of drug-induced parkinsonism was 14.4% (95% CI: 11.0 to 18.0) and it was 12.4% (95% CI: 9.3 to 15.4) for drug-induced akathisia. The result of the final model found out drug-induced parkinsonism was significantly associated with female sex, age, type of antipsychotics, physical illness, and anti-cholinergic medication use. Similarly, female sex, chlorpromazine equivalent doses of 200 to 600 mg, combined treatment of sodium valproate with antipsychotic, and severe khat/Catha edulis use risk level was significantly associated with akathisia. Conclusion One of seven patients developed drug-induced parkinsonism and akathisia. Careful patient assessment for drug-induced movement disorders, selection of drugs with minimal side