The length of the sentence is binding on the prisoner in undergoing the coaching period, which means that the prisoner loses his freedom for a while in accordance with the verdict that has been handed down. This can have an impact on mental health problems such as anxiety. The anxiety in question is related to the length of the sentence, because the longer the sentence, resulting in difficulties in adjusting to being released later, this causes inmates to experience anxiety while they are serving their sentence. The purpose of this study was to determine the relationship between length of sentence and anxiety about serving sentences for drug abuse convicts at the Class II B Penitentiary, Mojokerto. The research design used correlation analytic with cross sectional approach. The population of this study were all 386 prisoners, with a total sample of 79 respondents. The sampling technique used simple random sampling. Collecting data using a questionnaire. Based on the results of research from 79 respondents, 47 respondents (59.5%), very severe anxiety (20.3%), moderate anxiety 9 respondents (11.4%), mild anxiety 3 respondents (3, 8%), and no anxiety 4 respondents (5,1%). Spearman Rho statistical test results obtained a significant value of p value (0.001) < = 0.05, which means that H0 is rejected, meaning that there is a relationship between length of sentence and anxiety about serving sentences for drug abuse convicts at the Class II B Correctional Institution, Mojokerto. So it can be concluded that the longer the sentence, the more likely there is anxiety in prison.