The objective of this investigation was to analyze the gait of pregnant women per trimester of pregnancy and its relation with the BMI. The study used non-experimental, comparative and correlational methodology. The sample consisted of 25 women between ages 20 and 30, and were randomly selected. The gait was evaluated by considering floor reaction force by the pressure center on gait platforms, Artoficio and BIM, gotten from weight and height measured with stadiometer Seca model 700. The results show significant differences in weight, BMI, force during the support and thrust stage, left footstep duration, and work during the thrust stage among the trimesters. Besides there are correlations between BMI and some power variables and work during the support and thrust stages. After carrying out this investigation, one can conclude that the increase of the BMI might generate abnormalities of the gait under pregnancy conditions.El objetivo fue analizar la marcha por trimestre de embarazo y su relación con el índice de masa corporal. La metodología fue no experimental, comparativa y correlacional. La muestra fue de 25 mujeres de entre 20 y 30 años, seleccionadas no probabilísticamente. La marcha se evalúo por el comportamiento de la fuerza de reacción al piso por centro de presión en plataformas de marcha de fabricación Artoficio y el IMC a partir del peso y talla medido por estadiómetro marca Seca Modelo 700. Los resultados muestran diferencias significativas (p