IntroductionIn Nigeria, breast cancer (BC), a disorder marked by the unchecked growth of breast cells, has been the commonest cancer among women in Nigeria. Breast self-examination (BSE) is one of the suggested methods for screening for the early diagnosis of breast cancer. However, studies have reported inadequate knowledge, negative attitudes and poor practices of BSE among undergraduate female students. The study was designed as an interventional study to examine the effect of educational intervention on knowledge, attitude and practice of breast self-examination among female students in a private university in southern Nigeria.MethodsThis pretest posttest design study was carried out on 103 students of Novena University at baseline in 2022, which were chosen through the use of simple random sampling. A validated questionnaire with components on demographics, knowledge, attitude, and BSE practice was used to gather the data. After that, the students participated in three hourly sessions of an educational intervention for two weeks. A month later, the students’ data were once again collected, and SPSS 20 software was used to evaluate the results using the mean, paired t test, and logistic regression at the P < 0.05 level of significance.ResultsThe mean age of the respondents was 22.37 ± 1.92 years. Only 53 (51.3%) were aware of BSE. The mean knowledge, attitude and practice of BSE at pretest significantly increased at posttest after the educational intervention (1.58 ± 1.48 vs. 4.31 ± 1.15, 2.37 ± 1.27 vs. 4.80 ± 0.49 and 1.97 ± 0.09 vs. 5.81 ± 3.26, respectively). Furthermore, age and family history of BC were predictors of knowledge (OR = 4.00 95% CI = 0.29–41.99, OR = 141, 95% CI = 0.15–13.18), attitude (OR = 2.39, 95% CI = 0.28–12.32, OR = 1.15, 95% CI = 0.24–8.34) and practice of BSE (OR = 2.66, 95% CI = 0.38–18.41, OR = 1.44, 95% CI = 0.24–8.34) respectively.ConclusionThe findings showed that using an educational intervention strategy will improve the knowledge, attitude and practice of BSE among undergraduate students.