To evaluate the cost effectiveness and cost-utility the one-step scheme, recommended by the International Association of Diabetes and Pregnancy Study Group (IADPSG), compared with the two-step scheme, recommended by the American Diabetes Association (ADA) for screening and diagnosis of gestational diabetes mellitus in Colombia We designed a decision tree model that compared the effectiveness, based on a systematic literature review, and expected costs for each alternative. Outcomes included correctly diagnosed cases, pre-term births and other obstetric complications. Utility weights, in QALYs, were derived from the literature. The analysis was conducted from a third-party payer perspective, considering only direct medical costs both for normal pregnancy and associated complications, based on base cases designed by an expert panel, and resource use turned into prices using official tariff manuals. Time frame was from gestational week 24 until one month after delivery. Results were subject to univariate and probabilistic sensitivity analyses. Costs were in 2014 Colombian pesos (1 euro = COP 2,660). By using the one-step scheme average costs per pregnant woman were similar for the one-step (€ 476), or the two-step (€ 500) schemes. In terms of adverse maternal and neonatal outcomes, the one-step scheme shows better clinical performance and slightly more QALYs gained (0.06). A correct diagnosis would be reached in 921 and 853 women per thousand, respectively. One-step scheme averted 8 pre-term births per thousand. The results withstood the sensitivity analyses. A one-step scheme should lead to slightly lower expected costs and better clinical outcomes.