Composites reinforced with glass fibers are hybridized with flax. An analysis of tensile properties and fire properties were made depending on the type and stacking of the reinforcements. For the purposes of testing the mechanical properties, two types of composites were obtained by the vacuum infusion: the first composite was made of four layers of fibers with glass fibers in the outer layer and flax fibers in the middle. The second composite was made of four layers of glass fibers only. Composites are connected with epoxy resin. Tests were conducted on them in accordance with the standard HRN EN ISO 527 – 4: 1997 Plastics – Determination of tensile properties – Part 4: Test conditions for isotropic and orthotropic fiber – reinforced plastic composites. The values of tensile strength, tensile modulus of elasticity and ultimate elongation were determined. The results were compared with the minimum requirements of the Croatian Register of Shipping (CRS) for composites reinforced with glass fibers. The results showed that both composites meet the requirements. For the purposes of testing fire properties, two types of composites were made by manual lamination. In the first one, there are glass weaves in the outer layers and three linens between them, while in the second one, the weaves are arranged alternately, starting and ending with the linen. The test was carried out according to DIN 53 438, in two ways for both types of composites. Firstly, exposing the edge to a flame, where the results showed that the composite with flax fibers in outer layer will burn faster and secondly, surface exposure to flame, during which no composite material ignited.