Breast cancer is the leading cause of cancer in females worldwide. Western Africa has one of the highest mortality rates globally partly due to late presentation, often attributed to deficits in patient knowledge about the disease. A cross-sectional study was conducted at the Korle Bu Teaching Hospital among breast cancer patients. A structured questionnaire was utilised to collect data on patient demographics; sources of information on breast cancer; risk factors; symptoms; and treatment options. A chi-square test assessed the relationship between the participants’ levels of knowledge and demographic characteristics. Univariate and multivariate analyses determined which sociodemographic factors predicted knowledge. p values <0.05 were considered statistically significant. This study enrolled 636 participants with a mean age of 52.6 ± 12.1 years. Television (TV) (63.4%) and radio (44.6%) were the main sources of information about breast cancer. Thirty-two percent of participants knew that family history was an associated risk factor for developing breast cancer. Eighty-three percent of the patients were familiar with self-breast examination, but only 42% of them practiced it. While 76% of participants knew that a breast mass could represent breast cancer, only 13%, 12% and 6% of participants identified nipple discharge, breast skin changes and changes in breast size as concerning symptoms of breast cancer, respectively. Only 7% of patients were aware of breast conservation as a treatment option. A higher educational level and higher monthly income were identified as predictors of a better level of knowledge, while age older than 60 years and advanced-stage disease correlated with decreased knowledge about breast cancer. Breast cancer awareness campaigns in Ghana should be expanded to include all Ghanaians, specifically women of lower socioeconomic status and older than 60 years. Educational messages should emphasise symptoms other than breast masses and the feasibility of breast-conserving surgery as a treatment option for early-stage disease.