The main point of this study is to determi- ne the dimensions of the thorax and its relation to the ventilatory function of a group of swimmers members of the swimming team at Universidad Católica del Maule. 42 male subjects, whose age vary between 18 and 26 years old, were evaluated. 18 subjects were on the swimming team and 24 were sedentary students, all of them study in Universidad Católica del Maule. They were performed a basic bodily anthropometry assessment (weight and body size) and they were also performed a specific anthropometric assessment of the thorax, as well as one of the anteroposterior diameter (ATD) and the transverse diameter (TDT), thorax and the mesosternal perimeter (MP). Finally, they were performed an evaluation of the ventilatory function trough body plethysmography. For the statistical analysis the normality of the data was determined, then came the use of t of student or U of Mann-Whitney and Pearson or Spearman, depending of the case, whether it was to determine the statistical significance or correlation, respectably. A level of statistical significance of p> 0,05 was considered. A significant increase of the body mass index (BMI) was observed, bigger thorax dimensions, PDA to full pulmonary capacity (FPC) and PME to FPC and residual volume. In the ventilatory function there was a significant increase of maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP), inspiratory capacity (IC) and FPC. There were also correlations that vary from good to excellent between the diameter and perimeter of the thorax and IC and FMP, among the swimmers. Thus, it is concluded that relations exist between the anthropometrical of the thorax and the ventilatory function in swimmers of the Universidad Católica del Maule, Talca, Chile.