Resumo. Previous studies demonstrated the relationship between injury of the locomotor and increased urinary excretionof hydroxyproline (HP). The aim of this study was to evaluate the effects of muscular stretching on HP levels inmilitary men. Were evaluated 64 individuals (18,7 ± 0,5 years old; 63,8 ± 7,3 Kg) shared into: stretching group(GA: n=32) and control group (GC: n=32). Stretching was performed through the mixed method with three setsof four sub maximal insistences and four seconds of permanence at maximum reached point at the joint. The restinterval between the sets was about five seconds. Performing: scapula-umeral flexion and extension (FO and EO),hip-femural flexion and extension (FQ and EQ). The GC performed no physical exercises. The urine collection wasperformed: before the exercise (basal time), 24h and 48h after the exercise. The sample was analyzed through thecolorimetric method. The Shapiro-Wilk normality test and One-way ANOVA were undertaken, considering p<0,05as significance level. After of it, the Tukey post hoc test was done. There were reductions (D% = -4,26%) betweenthe basal time and 24h moments (p = 0,0001), and increase (D% = 5,53%) between the moments 24h and 48h (p= 0,0001), suggesting that occurred a return of HP levels to the basal time values 48h after the stretching exercise.We conclude that stretching exercise with the same characteristics of the used at the present study are safe, becauseseems do not cause damages in connective tissue.