Breast cancer remains a deadly disease, but early detection significantly improves the survival rate. This quasi-experimental study evaluated the effect of a health education intervention on breast cancer knowledge among women of childbearing age in selected communities in Ogoni, Rivers State. The study specifically examined the effect of health education on knowledge of breast cancer, and early identification of its signs and symptoms. The study population comprised 21,929 women from four Local Government Areas (LGAs) in Ogoni. A sample of 664 women was selected through a multi-stage sampling procedure. Data were collected using a structured instrument assessing breast cancer knowledge. Statistical analyses were performed with SPSS version 27, including percentage, mean, standard deviation, and analysis of covariance (ANCOVA) at a 0.05 significance level. The pre-intervention results indicated that only 45.9% of participants provided correct answers to breast cancer knowledge items. After the intervention, correct responses increased to 62.4%. Similarly, knowledge on early identification of breast cancer signs rose from 50.3% to 67.5%, and knowledge of BSE techniques improved from 49.1% to 67.5%. ANCOVA results showed significant intervention effects on breast cancer knowledge of breast cancer [F(1,632) = 903.45, p < 0.05], and early identification of signs and symptoms of breast cancer [F(1,632) = 580.77, p < 0.05]. This study concludes that health education is a valuable tool to enhance breast cancer knowledge among women of childbearing age in Ogoni communities. It is recommended that healthcare practitioners expand educational campaigns on early breast cancer detection and improve health outcomes.