Background. In Germany, the association between breastfeeding behaviour (BF) and socio-economic status (SES) has not been studied in detail. However, ancillary reports from epidemiological research pursuing different objectives provide some information. Methods. This systematic review, based on the search engine 'MEDLINE', summarizes the available information regarding initiation and duration of breastfeeding in the upper and lower social groups in Germany. Recommendations to enhance breastfeeding behaviour are presented. Results. Fifteen studies with relevant information were identified. The paper with the smallest number of cases did not detect any differences between social groups, but all other studies reported a clear association of BF and SES, with mothers of the lower social groups breastfeeding significantly less frequently. Eight other study groups collected data on BF and SES but did not link them together. Conclusion. Breast milk is known to be the very best nutrition for infants up to the age of 6 months. Despite a renaissance of breastfeeding after 1970, BF must still be encouraged in Germany, especially in women with lower SES. The concept of 'diffusion of innovations' by EM Rogers provides some explanation of these differences between socio-economic groups.