A team of experts from the fields of gynaecology and obstetrics, diabetology, internal medicine, paediatrics and midwifery from Germany, Austria and Switzerland produced a new version of the existing S3 guideline on gestational diabetes. It replaces the recommendations of the German Association for Gynaecology and Obstetrics and the German Diabetes Association on the diagnosis and treatment of gestational diabetes from 2011 and is valid for the three German-speaking countries. The primary aim of the guideline is to improve and standardise the prevention, screening, diagnosis, treatment and follow-up of gestational diabetes through evidence-based recommendations for the outpatient and inpatient area. A large number of new studies and data published in the last few years required a comprehensive revision of the 2011 guideline. The new aspects include early screening of pregnant women with a high risk for diabetes or gestational diabetes, the validity of two-stage screening in the third trimester by means of the 50-g challenge test, as specified in the maternity guidelines, use of metformin instead of or in addition to insulin in gestational diabetes, and birth planning with GDM and/or macrosomia. The recommendations are based on the evidence from the literature, which was selected through a systematic external literature search. All recommendations had to pass through a consensus process. The present text corresponds to the practice guideline on gestational diabetes, which is an action-oriented short version of the evidence-based S3 guideline that can be viewed on the internet.