A key trend in the PVC market is to replace or decrease the amount of phthalate plasticisers used due to increasing health concerns. Therefore, the demand for non-phthalate based plasticisers is growing rapidly. Mineral oils are used in a variety of rubber and polymer applications as plasticisers; however, due to the lower polarity their applicability in PVC compounds is limited. Therefore, these materials are typically used as secondary plasticiser along with a primary for the purpose of improved properties and cost reduction. Some of the non-phthalate based solutions are fast fusing plasticisers, which act like solvents and have too rapid and too high plasticizing effect. This makes the compounding difficult and could cause problems in production. These substances have good compatibility with mineral oils, and using them together in PVC compounds can help the compounding issue by reducing the solvent power and increasing the fusion time to a level where the production parameters are similar to compounding with phthalates.   The aim of this study was to evaluate the use of mineral oils as a secondary plasticiser in a non-phthalate system for PVC. Four different grades of mineral oil and three non-phthalate plasticisers were used in compounding and compression moulding of PVC sample films. Mechanical, physical and chemical testing were done to assess the properties in a comparative study with phthalate plasticized PVC.   Tensile testing and hardness measurements showed that the mineral oils did not contribute with any plasticizing effect for the non-phthalate plasticisers tested in the study. The hardness was instead slightly increased for all the sample films that contained mineral oil. This indicates that the mineral oil either is less efficient than the primary plasticiser or that it affects the primary plasticisers intramolecular shielding between the PVC chains.       The shrinkage test showed that the migration of mineral oil was acceptable, especially the thicker grades of mineral oils had low migration. Colour stability test showed that the thicker mineral oil grades had some problems with discolouration. The discolouration is probably related to content of polyaromatics and oxidation stability.