Polypropylene fibers belong to the group of synthetic fibers which because of their properties, positive effects and affordable price are most often added to cement composites. The paper presents the results of tests of the effects the variation of the length of two types of polypropylene fibers has on certain properties  of  mortar  in  hardened  state.  On  the  occasion  of  making  the  mortar,  polypropylene multifilament fibers and fibrillated fibers were added, in the amount of 900 g/m3, whereby the length of the fibers was: 6 mm, 12 mm and 18 mm. The hardened mortar was tested for the following properties: density of hardened mortar, compressive strength, flexural strength and mortar shrinkage in air. In general it can be concluded that the flexural strength increase is correlated with the fiber length increase. Also, it was determined that the addition of fibers has a positive effect on the reduction of mortar shrinkage due to drying in the period from 4 to 28 days.