Background: Tuberculosis (TB) generally considered as an ambulatory disease. However, hospitalization remains an important component for isolation and medical stabilization of patients. Hence, this study aimed to identify factors influencing the length of hospital stay during the intensive phase of multidrug resistant tuberculosis treatment at Amhara Regional State hospitals, Ethiopia: retrospective follow up study.Methods: An institution based retrospective follow up study was conducted at three hospitals, namely the University of Gondar comprehensive specialized, Borumeda and Debremarkos referral from September 2010 to December 2016 (n=465). Data were extracted from hospital admission/discharge logbooks and individual patient medical charts. Logistic regression was used to identify factors associated with longer hospital stays during the intensive phase of multidrug resistant tuberculosis treatment.Result: Most patients (92.5%) had a pulmonary form of multidrug resistant tuberculosis and a quarter of them HIV co-infections. The median length of hospital stay was 61 (interquartile range 34 to 101) days. The pulmonary form of tuberculosis (Adjusted odds ratio [AOR], 3.20, 95% confidence interval [CI]; 1.28 to 7.96), treated at the University of Gondar (AOR= 2.11, 95%CI; 1.02 to 4.41) and Borumeda Hospital (AOR= 3.59, 95%CI; 1.67 to 7.72), functional status of ambulatory (AOR=2.25, 95% CI; 1.19 to 4.27) and bedridden (AOR= 3.39, 95%CI; 1.57 to 7.35), and reported adverse drug reactions (AOR=2.54, 95%CI; 1.60 to 4.02) were significant predictors of extended hospital stays.Conclusion: The study revealed that longer hospital stay and significant differences were observed among hospitals. Decreased functional status at admission, pulmonary form of tuberculosis and reported adverse drug reactions were determinants of longer hospital stays. This underscores the importance of early case detection and prompt treatment of adverse effects.