Dissertation (MSc Nursing Education)Background: Learning by clinical practice is one of the most important components in nursing educational programs, considering that nursing is a practice-based profession. Objective: The aim of this study was to assess clinical learning environment and the clinical performance among pre-service nursing students in Tanzania. Method: A cross-sectional analytical design using quantitative approach was employed. Purposive, stratified and systematic random sampling was used to select nursing training institutions, course program and pre-service nursing students respectively. Data were collected through structured self-administered questionnaires. Data was analyzed by using Statistical Product of Social Solution version 25. Results: In this study, 426 respondents were studied, 254 (59.6%) males and 178 (40.4%) female. A total of 302 (70.9%) were degree programme students and 124 (29.1%) diploma. A total of 200 (46.9%) respondent were from the University of Dodoma and 67 (15.7%) were from Zanzibar University. Slightly more than half 237 (55.6%) of the respondents reported that clinical learning environments were not conducive, it was found that, degree nursing students were 2.183 (AOR) times more likely to perceive clinical learning environment to be conducive against diploma nursing students (p<0.05, CI: 1.151; 4.139). A total of 233 (54.7%) respondents were not satisfied with the clinical learning environment and degree nursing students had 3.944 times more likely to be satisfied with clinical learning environment than diploma nurse students (AOR= 3.944, p<0.001, 95% CI: 2.028; 7.670). The results of overall performance for degree and diploma students show that about 406 (95.3%) have higher clinical performance. Conclusion: Nursing students in Tanzania perceive clinical learning environment as being not conducive for effective and efficient learning process. Therefore, the study recommends among other things, to promote conducive clinical learning environment and to undertake longitudinal studies so as to establish the evidence of presence or absence of association between CLE and CP.