In this report, we used ab initio calculations in order to study the effect of Pt doping in monolayer MoS2. The Pt doping introduces important distortions at the geometrical levels, that induces the appearance of impurity levels, expressed as flat bands, in the proximity of the Fermi level, thus reducing the band gap. The vibrational analysis confirms the reduction of symmetry, and the simulated off-resonance Raman spectra presents important differences when comparted with pristine MoS2 monolayer, with relevant bands located at similar to 50, 150, 220, 300 and 330 cm(-1). All this confirm that Pt doping could be possible, allowing electronic and vibrational tuning of their properties and this work provides the tool for a potential identification of these modifications at the experimental level.