We investigated the impacts of breast cancer diagnosis and treatment on employment status and the ability to perform occupational and housekeeping tasks. We performed a cross-sectional study to compare Korean breast cancer survivors (n = 1,594) who had been working before cancer diagnosis with a group of 20 to 60-year-old women from the general Korean population (n = 415). Employment decreased from 47.6% to 33.2% after cancer treatment. It was significantly smaller relative to the general population (52.1%) [adjusted odds ratio (aOR) = 1.68; 95% confidence interval (CI): 1.35-2.11). There was an inverse association between employment and low levels of education, low household income, multiple comorbidities, disease stage, and mastectomy. In addition, women who lived with a spouse were more likely to quit working after treatment compared to women who had no spouse. Fatigue and exhaustion were the most frequent difficulties encountered during occupational work (by 46.8% of cancer survivors) and housework (64.6%). Our findings suggest that breast cancer has a greater impact on employment among Korean women than among women in previously studied Western populations. Our data suggest that socio-cultural factors, as well as certain clinical characteristics, influence the decisions of Korean women to return or to not return to work after surviving breast cancer.