BACKGROUND Emerging evidence indicates that some hematological markers have critical value in evaluating treatment response. This study was performed to determine the clinical value of hemoglobin (Hb), platelet (Plt), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) in rheumatoid arthritis (RA) patients treated with tocilizumab (TCZ). METHODS Fifty-two RA patients receiving TCZ were recruited and followed for 6 months. The values of abovementioned hematological markers were collected. Clinical disease activity index (CDAI) and disease activity score based on 28 joints (DAS28)-ESR were calculated. Correlation analysis was conducted by calculating Pearson's correlation coefficient. The change in disease activity between groups according to the baseline level of hematological markers was compared by t test. RESULTS Significant correlation between change in NLR (△NLR), change in PLR (△PLR), and change in CDAI (△CDAI) was found (△NLR: r = 0.30, P = 0.03; △PLR: r = 0.31, P = 0.03). The change in Plt (△Plt) was correlated with change in DAS28-ESR (△DAS28-ESR) (r = 0.36, P = 8.24 × 10-3 ). Greater improvement in CDAI was seen in patients categorized into Plt high group (t = 2.06, P = 0.04), NLR high group (t = 2.15, P = 0.04), and PLR high group (t = 2.41, P = 0.02) compared with the contrast group. CONCLUSIONS Our study demonstrated that △Plt, △NLR, and △PLR could be used to monitor the clinical response to TCZ. RA patients with high baseline levels of Plt, NLR, and PLR achieved more improvement, indicating these hematological markers might be utilized to guide TCZ treatment.