Abstract Objectives : There is limited evidence on patient satisfaction with clinical laboratory services in Northwest Ethiopia. This study aimed to assess patient satisfaction with clinical laboratory services and associated factors among adult patients attending outpatient departments at Debre Markos hospital, Northwest Ethiopia. Cross-sectional study was conducted among 391 patients from April 09-16, 2019 using interviewer-administered questionnaire. Systematic random sampling technique was used. Data were entered into Epi-Data software version 4.2, and analyzed using SPSS 23. Binary logistic regression analysis was employed. Variables having p-value < 0.05 were considered as statistically significant. Results: Overall level of patient satisfaction towards clinical laboratory services was 48.3%. Patients with no occasion of missing laboratory results [AOR: 2.10; 95% CI (1.13, 3.83)], had diplomas and above educational level [AOR: 0.38; 95% CI (0.15, 0.96)], and who reported no place in the laboratory to put personal things [AOR: 0.37; 95% CI (0.21, 0.54)] were significant factors. Hospital administration and laboratory department in Debre Markos hospital should strengthen their effort to improve patient satisfaction focusing on educational status of patients, missing laboratory results, and the availability of places to put personal things in the blood drawing room. Key words: Debre Markos hospital; Patient satisfaction; Laboratory services