Background The aim of the study was to assess the prevalence of back pain in non-professional Brazilian jiu-jitsu (BJJ) athletes, and to assess the relationship between their back pain and postural disorders. Methods The study involved 61 subjects: 31 subjects who trained Brazilian jiu-jitsu and 30 subjects who had never trained any martial arts. The mean BJJ training time in the study population was 3.89 ± 4.13 years. The athletes’ trained 4.06 ± 2.8 times a week and took 1.5 hours. Postural assessments were conducted with the use of the photogrammetric method. The assessment of back pain and injuries was conducted with the Oswestry Disability Index (ODI) and with our proprietary questionnaire. Results Among both populations, 37 subjects reported back pain − 22 athletes (71.0%) and 15 controls (50%) (p = 0,094). There were no differences in back pain location between the two groups (p > 0.05) or in functional state on the Oswestry Index (21.5% in the study population and 20% in the control group, p = 0.121). We observed significant differences between the groups in the values of four of the postural parameters. For each of these four parameters, parameter values were higher in the study population: DCK-spinal height from C1 to S1 (474.8 ± 25.4 vs 447.1 ± 25.9, p = 0.001); RKP-length of kyphosis between C7 and thoracolumbar junction (321.9 ± 15.2 vs 307.3 ± 22.2, p = 0.010); RLL-length of lordosis between S1 and thoracolumbar junction (152.9 ± 18.2 vs. 139.8 ± 17.6, p = 0.009) and KNM-pelvis inclination angle (2.24 ± 1.18 vs. 1.64 ± 1.34, p = 0.041). We found statistically significant differences in the study population between the athletes with and without back pain. These differences were found in the following parameters: RKP-length from C7 to peak of kyphosis (p = 0.01) and TT-difference between height of the waist triangles (p = 0.018). Conclusions There are no differences in back pain in regard to its frequency, intensity and location between non-professional BJJ athletes and subjects who do not train BJJ. Both in the study population and in the control group the spinal pain was minimal or moderate on the Oswestry Disability Index. BJJ athletes who reported back pain had characteristic postural changes in some of the analysed postural parameters in comparison to BJJ athletes who did not report back pain.