The Child Development Evaluation (CDE) Test is a screening tool designed and validated in Mexico for the early detection of child developmental problems. For professionals who will be administering the test in primary care facilities, previous acquisition of knowledge about the test is required in order to generate reliable results. The aim of this work was to evaluate the impact of a training model for primary care workers from different professions through the comparison of knowledge acquired during the training course. The study design was a before/after type considering the participation in a training course for the CDE test as the intervention. The course took place in six different Mexican states from October to December 2013. The same questions were used before and after. There were 394 participants included. Distribution according to professional profile was as follows: general physicians 73.4%, nursing 7.7%, psychology 7.1%, nutrition 6.1% and other professions 5.6%. The questions with the lowest correct answer rates were associated with the scoring of the CDE test. In the initial evaluation, 64.9% obtained a grade lower than 20 compared with 1.8% in the final evaluation. In the initial evaluation only 1.8% passed compared with 75.15% in the final evaluation. The proposed model allows the participants to acquire general knowledge about the CDE Test. To improve the general results in future training courses, it is required to reinforce during training the scoring and interpretation of the test together with the previous lecture of the material by the participants. Copyright © 2015 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.