The objective was to evaluate the influence of water deficit on the growth and development of Amaranthus deflexus L. after the application of herbicides with different mechanisms of action. The experimental design used was completely randomized with a double factorial arrangement and split plots over time. Analysis of variance was performed using the mixed model methodology. For total dry mass, plant height, stem diameter, relative water content and chlorophyll content, weeds were subjected to three factors: products (water, glyphosate, diuron, nicosulfuron and 2.4-D), and water conditions (100, 60 and 30% of the tray capacity), applied in different times after the application of the product (0, 2, 4, 6 and 8 days) nested in the subplots. To evaluate the phytotoxicity scale, analyses were carried out from the second to the eighth day after herbicide application. At the end of the trial, there was a reduction in the magnitude of quantitative plant growth traits of A. deflexus L. due to the application of herbicides associated with water stress conditions. For the random variation resulting from the nested effect of time in the subplots, a decreasing trend was observed for the characters plant height, stem diameter, total dry mass, total chlorophyll content and relative water content, as well as an increase in plant phytotoxicity weeds until the eighth day after herbicide application, with an increase in the length of the evaluation subintervals.