Most women interrupt their work activities during the treatment of cancer. This study investigated return to work (RTW) after treatment of breast cancer in the period from January 2002 to December 2008. ArboNed Occupational Health Service records the sickness absence and RTW data of more than one million workers of whom approximately 40% are women. Incident cases of sickness absence due to breast cancer (ICD-10 code C50) were selected from the ArboNed register. Proportions of partial RTW, with 50% of the earnings before sickness absence, and full RTW were determined 1 year after diagnosis. Trends in partial RTW and full RTW were examined by Chi-square trend analysis. The time to partial RTW and full RTW was analysed by Cox regression and stratified by age (<40 years, 40-50 years and >50 years). The proportion of partial RTW was stable around 70% from 2002 to 2008. The proportion of full RTW decreased from 52% in 2002 to 43% in 2008 and showed a linear decline in women of all ages. The time to partial RTW and full RTW in the years 2003-2008 did not change significantly compared with 2002. In the Netherlands, the proportion of employed women who fully resumed working after breast cancer within 1 year of diagnosis has decreased since 2002. These results warrant more epidemiological research to examine the trends in RTW of breast cancer survivors across countries.