BACKGROUND We evaluated the role of scuba diving on cardiovascular risk in a small group of divers. METHODS We have enrolled 14 subjects (12 males and 1 female, mean age 49±12.2 years) undergone to scuba diving (one patient did not complete the period of observation due to the b-blocker treatment). We evaluated electrocardiographyc trace and we have measured QT and RR interval to calculate the QTc index (Bazzet, Fridericia, Hodges and Framingam index) and the Tpeak to Tend index and heart rate variability index before and after scuba diving activity. RESULTS The results of our study confirm that there is a statistically significant improvement of the RR and QT index but there is not a statistically significant increase of the QTc index (QT interval normalized by heart rate) evaluated before and after scuba diving. In the same cohort of subjects, we have noted a not statistically significant improvement of Tpeak to Tend index. Our study has underlined a statistically significant modification of the SD1 and SD2 indices representative of parasympathetic and orthosympathic activity. Scuba diving activity seems to not be associated with a statistically significant variation of the cardiovascular risk. CONCLUSIONS Our data confirm that non-linear analysis is characterized by a statistically significant variation of the neurovegetative tone mainly linked to an increased parasympathetic activity. However, further studies are necessary to elucidate these preliminary findings.