Bougainvillea spectabilis Willd. is an interesting plant for home and urban landscaping, since it blooms throughout the year and shows a wide variety of bract colors, in addition to being tolerant to water stress. The rooting of stem cuttings of bougainvillea is usually small and could be associated with the type of substrate that is used. The objective of this work was to evaluate the substrate effects on rooting response of bougainvillea stem cuttings. Two experiments were carried out in a completely randomized design with ten replications. The treatments were: ‘red sand’ (RS), ‘coarse sand’ (CS), RS + CS, RS + weathered carnauba straw (Copernicia cerifera Mart.) (WCS), CS + WCS, and RS + CS + WCS. The analysis of a CS sample indicated an apparent density of 1.21 mg m-3, moisture retention of 8.00 (0.01 Mpa), 10.2 mm and 51.03 mm m-1 available water and, the following components expressed as g kg-1: 904 coarse sand, 85 fine sand, 4 silt, and 7 clay. The corresponding values for RS were 1.20 mg m-3, 10.96 (0.01 Mpa), 5.52, 13.1 mm, 65.28 mm m-1 and 405, 556, 5, and 34 in the granulometric fractions. Greater rooting percentages were obtained with the use of CS (24%) or CS + RS (28%). In the second experiment, WCS was replaced with vermicompost (VC). Greater rooting percentages were obtained with CS + VC (73%).