The prevalence of diabetes mellitus in all of its forms is increasing, but especially type 2 and gestational diabetes due to their association with obesity. Although many will be under the care of a multidisciplinary team, including obstetricians, diabetologists, specialist nurses and dieticians during pregnancy, primary care is the ideal setting for much of the essential pre-pregnancy care and ongoing postnatal support. This is a patient group that can be difficult to manage, especially if there are issues of non-concordance with treatment. The aim of this article is to provide an overview of diabetes in pregnancy, with particular focus on what the best care will look like in general practice. It begins with some background information and continues by looking at each stage of the pregnancy from pre-conceptual advice, through to postnatal and long-term care.