IntroductionMenstrual hygiene management practice is the requirements and necessities; such as the use of a sanitary pad or clean and mushy absorbents, sufficient washing of the genital area, proper disposal of the used absorbents, and other special needs for the women during menstruation.ObjectiveTo assess menstrual hygiene management practice and associated factors among prisoners in south Nation Nationalities and Peoples Region, Ethiopia, 2022.MethodsAn institution-based cross-sectional study was conducted from May 1 to July 30/2022. The total sample size was 605 and a simple random sampling technique was used to select prison institutions and women. The data were collected through face-to-face interviews. Data were entered using Epi data 4.6 version and analyzed by using SPSS version 26 software. Multicollinearity was checked and the goodness of fit test was done by using the Hosmer Lemeshow model of goodness fit test. Univariate analysis was done and variables with p value less than 0.25 were taken to bivariate logistic regression analysis. Adjusted odds ratio with the 95% confidence interval was considered and statistical significance was at a p-value less than 0.05 in bivariate logistic regression analysis.ResultThe prevalence of menstrual hygiene management practice was 50.6% (95% CI 47.3–54.4). Age 19–29 years old [AOR: 5.03, 95% CI 1.73–14.62], educational status; not formally educated [AOR: 0.05, 95% CI 0.02–0.13], educational status; primary level [AOR: 0.17, 95% CI 0.07–0.39], previous occupation; student [AOR: 2.56, 95% CI 1.06–6.21], previous occupation; a private employee [AOR: 4.11, 95% CI 1.48–11.42], previous occupation; government employee [AOR: 3.46, 95% CI 1.18–10.14], absence of support from family [AOR: 0.14, 95% CI 0.08–0.24] and absence of work engagement in prison [AOR: 0.44, 95% CI 0.25–0.78] were associated with MHMP.ConclusionIn this study, about five from ten women in prison practice menstrual hygiene management. Age, educational status, previous occupation, support from family, and work engagement in prison were important risk factors for MHMP. Therefore, support from family and engaging the women to work in prison institutions may increase the MHMP in prison institutions.