Maternal diabetes mellitus (types 1 and 2) is the most chronic prevalent medical condition affecting the pregnant population and is associated with a less satisfactory pregnancy outcome for both mother and infant when compared with the non-diabetic population. Most reports have focused on women with type 1 disease, type 2 disease being perceived as a less serious condition. However, type 2 disease is far more common (and is increasing) in some areas of the UK, especially where there is a high proportion of women from the Indian subcontinent. This paper shows that pregnancy complicated by type 2 diabetes mellitus is a high-risk state, with miscarriage and congenital malformations almost twice that seen in type 1 disease. These adverse outcomes are contributed to by poor attendance for pre-pregnancy care, later booking for antenatal clinic and poor glycaemic control at booking. Offspring of pregnancies complicated by type 2 diabetes are more likely to be delivered before 37 weeks gestation and be large in size for gestational age. We must dispel the myth, in women of childbearing age and in their healthcare providers, that diabetes treated with diet and/or tablets (type 2) is a less serious problem than type 1 disease.