Background During the past decades, several unconventional strategies for controlling chronic inflammatory diseases, including psoriasis, have been developed. The use of probiotics has been gaining importance as an adjuvant therapy in the treatment of these pathologies. Objectives Evaluate the impact of the use of the Lactobacillus rhamnosus probiotic strain in patients diagnosed with common and palmoplantar psoriasis. Methods 35 patients were randomly divided into two groups: 18 using probiotics and 17 using placebo. They were evaluated on days 0 and 60, with photographic records of lesions, IL17 and IL23 quantification and calculations of Psoriasis Area Severity Index (PASI), Body Surface Area (BSA) and Dermatology Life Quality Index (DLQI) clinical evaluation scores. Results There was significative improvement in the clinical presentation and a reduction in the index of all clinical scores (PASI from 4.53 ± 4.457 to 3.57 ± 3.333, BSA from 5.44 ± 6.451 to 4.94 ± 5.961 and DLQI from 8.83 ± 8.631 to 7 ± 7.814, in the probiotic group.) However, there was no reduction in the quantification of IL23 and IL17. Adverse events related to the use of probiotics were minimal. Conclusions There was a Positive correlation between the use of probiotics and improvement of clinical aspects and clinical scores of disease severity, not associated with reduction in interleukins 17 and 23 blood levels.