BACKGROUND: We aimed to identify the quality of life (QoL) of patients with psoriasis, to determine the possible differences depending on the therapeutic modalities (biologic, conventional treatment and phototherapy), and to examine other variables that could affect the success of the treatment. METHODS: This research was a non-experimental, quantitative, observational study that included 183 psoriasis patients. The study was conducted from November 2021 to December 2022 at the University Clinical Center Kragujevac, Serbia. The following instruments were used: Dermatology Life Quality Index (DLQI), Psoriasis Area and Severity Index (PASI), as well as a general questionnaire that contained a set of questions which referred to sociodemographic data. RESULTS: There was a statistically significant difference in the average values of the DLQI score concerning the application of different therapeutic modalities (<0.001). Biologic treatment was the modality with the lowest impairments in the QoL domain (average value of DLQI score 10.6±7.3), followed by patients on conventional treatment (average value of DLQI score 12.9±7.9), and the highest levels of impaired QoL were in patients who received phototherapy (average value of the DLQI score 13.7±9.3). CONCLUSION: Patients on biological therapy at all four time points individually (baseline, 4, 12 and 16 weeks) had the lowest average values of the DLQI score, i.e. the best QoL compared to subjects who received other therapy.