The goal of this research was to characterize the interior acoustics of high schools sports facilities using objective parameters. In situ measurements were done in 68 school gymnasiums in Portugal (volume from 450 to 2680 m3) regarding LAeqBN (background noise without gym classes), LAeqPE (ongoing Physical Education classes), RT, and RASTI. The results for LAeqBN were from 34 dB (L90) to 50 dB (L10) with a median of 42 dB. For the LAeqPE were found values from 75 dB (L90) to 85 dB (L10) with a median of 80 dB. For the RT(500/1k/2k) room values from 2.6 s (RT90%) to 6.9 s (RT10%) with a median of 4.8 s, were measured. The room average RASTI values were from 0.27 (RASTI90%) to 0.43 (RASTI10%) with a median of 0.34. These sports rooms proved to be highly reverberant, almost without sound absorbing materials, which might be harmful, especially for the gym teachers. The subjective perception of the PE teachers was analyzed through questionnaires where it was verified that they feel most discomfort when it comes for noise (and thermal) conditions. This was supported by the objective results obtained. Ideal values for those acoustic parameters are presented.