This work is focused on the evaluation of the structure and properties of the nucleated polypropylene (PP) fibres prepared by melt spinning technique at lower take-up velocities as pre-oriented fibres (POY) containing 0.3–1.5 wt. % of additives - nucleating agents like 1,3:2,4-dibenzylidene sorbitol (DBS), quinacridone (QA) and calcium carbonate (CC). The thermal properties of nucleated PP fibres were determined by using differential scanning calorimetry (DSC). Used additives promote nucleation activity, DBS and QA better than CC, as they increased the crystallization temperature to higher extent than CC. Effect of CC seems to be negligible, due to very little impact on melting point and crystallization temperature. Morphological characteristic of the PP fibres were observed by means of scanning electron microscopy. The morphology of nucleated PP is different significantly from that of reference non-nucleated PP fibre. The measured values of the above mentioned properties were compared with parameters of non-nucleated PP fibre prepared under same technological conditions.