The aim of this study was to assess the responsiveness to change of the quality of life evaluated by the EuroQol Five Dimensions Questionnaire (EQ-5D) and Hospital Anxiety and Depression Scale (HADS) after biological treatment in a population of rheumatoid arthritis patients. A cohort of patients with RA (n = 29) treated with tocilizumab (TCZ) were analyzed in the study. The inclusion criteria were patients aged between 18 and 65 years, fulfilling American College of Rheumatology 1987 criteria for RA. All patients had inadequate response to methotrexate and with no prior biologic exposure. They were evaluated clinically including Disease Activity Score 28 (DAS28), and the European Quality of Life 5 Dimensions (EQ-5D) to measure the quality of life, and HAD assessed the anxiety and depression status at the initiation of treatment with anti-IL 6 receptor antibody agent and after 6 months. Sensitivity to change was quantified by the effect size (ES) before and after the treatment with TCZ. Among 29 patients with RA included in the study, 25 were females and 4 males. The mean age was 42 years ± 13.4 (SD). Three patients were excluded from the study before 24 weeks because of serious side effects, and five have missing data. The study population exhibited significant decreases in all measures of disease activity at 24 weeks. Physical activity expressed by the Health Assessment Questionnaire (HAQ) score increased through the observation period (for all p < 0.001). Sensitivity to change was high for the VAS and EQ-5D (ES 1.58 and 1.36, respectively) but only moderate for the HAD anxiety component (ES = 0.70) and small for the HAD depression component (ES = 0.4). The EQ-5D and VAS were more responsive than HADS to evaluate the quality of life on patient with RA treated with TCZ.