The purpose of this study was to develop a brief measure to assess knowledge regarding diabetes in pregnancy (Diabetes in Pregnancy Knowledge Screen [DPKS]). A test-retest design was used for subjects enrolled in a diabetes in pregnancy program at a university hospital. There were 58 women with overt diabetes (OD; insulin dependent and non-insulin dependent) and 67 women with gestational diabetes (GD). Three forms of the DPKS scale were developed for use with women with OD and women with GD treated or not treated with insulin. Adequate readability, internal consistency (r = 0.71), and testretest reliability (r = 0.76) were demonstrated with the DPKS. Initial support for the validity of the measure is suggested by its ability to differentiate women with GD versus OD, women on insulin versus those who are diet controlled, and women with shorter versus longer duration of illness. The DPKS may prove a useful clinical tool for diabetes educators working with pregnant women.