We present in this work Stark broadening calculations for 12 Ar XII and 12 Ar XIV lines. We present also their radiative atomic and collision data (energy levels, radiative decay rates, line strengths, oscillator strengths and collision strengths). Our Stark broadening data have been obtained using our quantum method in the impact approximation frame and including fine structure effects in the structure study. Our results are provided for the range of temperatures from 5×10 5 to 5×10 6 K of interest for plasmas investigations, and at electron density N e = 10 18 cm −3. The radiative atomic data have been calculated using the UCL code SUPERSTRUCTURE. The collision strengths have been calculated using the two UCL codes DISTORTED WAVE and JAJOM. Good agreement have been found between our atomic results and other theoretical and experimental ones. Our Stark broadening data are the first to be published, so no comparisons have been performed for them.