Study goal: The research objectives are monitoring the impact of biological therapy on the quality of life of patients with active rheumatoid arthritis, and the impact on the reduction of pain and disease activity in patients on biological therapy. Study drafting: A retrospective study was conducted at the Internal Clinic, University Hospital Osijek. Methods and participants: The study included 18 patients with rheumatoid arthritis treated with biological therapy. Data were collected from medical records, using standardized questionnaires of disease activity (VAS) and by monitoring the quality of life (HAQ) of patients with rheumatoid arthritis before the introduction of biologic therapy, 6 and 12 months after the introduction of biologic therapy. The questionnaire includes socio-demographic data (age, gender, occupation, diagnosis) and 20 questions relating to the quality of life of respondents assessed on a Likert scale. The patient’s assessment of disease activity due to pain (VAS) evaluates the disease activity from 0 (no activity) to 100 (the most powerful activity). Results: Statistically significant difference was found between the quality of life of patients according to the observed period, p = 0.003, and a statistically significant difference between the disease activity of patients according to the observed period, p = 0.001. Conclusion: In relation to the results obtained by this research, we can conclude that the quality of life of patients improved 6 and 12 months after the introduction of biologic therapy compared to the period before the introduction of biologic therapy, and the disease activity was lower. There was no connection between sex, duration of illness to initiation of treatment with biologic therapy and age in relation to the quality of life. Because of the small number of patients, statistically significant difference was not found, therefore it is needed to perform an investigation with a larger group of patients.