Abstract In this work, all existing smartphone and web applications for the calculation of the PMV index running on different platforms for mobile devices have been compared with a reference software compliant with ISO 7730 Standard. Unfortunately, only four apps take into account all the six variables responsible for the thermal sensation (air temperature, mean radiant temperature, air velocity, relative humidity, metabolic rate and clothing thermal insulation) and in some cases data input appeared very hard (e.g. impossibility to consider decimal values). In addition, only one app seemed to take into account the correction of basic clothing insulation values due to pumping effect. Based on results from this preliminary test, we can conclude that web apps and smartphone tools for the evaluation of thermal comfort conditions by means of PMV presently on the market have to be used with special care (or, better, should not be used) especially by not skilled users could use them even for professional reasons.