Purpose To explore future diagnosis-specific sickness absence and disability pension among women with breast cancer compared with women without breast cancer. Also, to examine associations with disease-related and sociodemographic factors among those with breast cancer. Methods Longitudinal register data on 3,547 women living in Sweden (age 20 to 65 years) who were first diagnosed with breast cancer in 2005, and a matched comparison cohort (n = 14,188), were analyzed for the annual prevalence of diagnosis-specific sickness absence and disability pension over 5 years. Logistic regressions were used to explore associations of disease-related and sociodemographic factors with future sickness absence and disability pension among women with breast cancer. Results Immediately after being diagnosed with breast cancer, the proportion of women with sickness absence was high but decreased continuously from the 1st through 5th year after diagnosis (71%, 40%, 30%, 22%, and 19%, respectively). In comparison, the range for women without breast cancer was 17% to 11%, respectively. The higher prevalence of sickness absence after breast cancer was mainly a result of breast cancer diagnosis, not a mental diagnosis, or other somatic diagnoses. Advanced cancer at diagnosis, > 90 days sickness absence before diagnosis, low education, and being born outside Sweden were associated with higher odds ratios for sickness absence and disability pension (odds ratio range, 1.40 to 6.45). Conclusion The level of sickness absence increased substantially in women with breast cancer during the first year after diagnosis and approached the level of breast cancer-free women in the following years; however, even in the first year, most women were not on sickness absence for a substantial time, and even in high-risk groups, many were not on sickness absence or disability pension in the following years. Information about relatively low future sickness absence and disability pension levels can be used by patients when planning their work, by health care professionals, and by social insurance officers. Employers and Occupational Health Services need this information to adequately handle workplace adjustments.