Background: In patients with rheumatoid arthritis (RA), hematological indices and ratios have been reported to be related to the severity of illness, and thus could potentially be useful determinants of quality of life (QoL). Objective: To evaluate the association between hematological indices or ratios, which serve as biomarkers of disease activity, and the QoL of RA patients. Materials and Methods: This study was carried out in the Rizgary Teaching Hospital in the Kurdistan region of Iraq between December 01, 2021, and March 31, 2022. All female patients with a confirmed diagnosis of RA and aged ≥18 years were included. Data relating to the disease activity score (DAS-28), biochemical measurements of the profile, and hematological indices and ratios were assessed. The QoL of each patient was assessed using the Quality of Life-Rheumatoid Arthritis II (QoL-RA II) and the World Health Organization-Quality of Life (WHOQOL-BREF) scales. Results: A total of 81 participants were included, with a median disease duration of 9 years. The median values of the hematological indices were as follows: mean corpuscular volume, 80 fL; platelet count 282 × 10 3 /mm 3 ; mean platelet volume, 9.7 fL; neutrophil-to-lymphocyte ratio, 2.76; and platelet-to-lymphocyte ratio, 170.5. In six of the eight domains of the QoL-RA II scale, the median score was ≤5, indicating poor QoL. The transformed scores of WHOQOL-BREF domains were <50. Multivariate regression analysis showed significant inverse correlations between plateletcrit and the health domains. The area under the curve of the physical, psychological, and environmental domains was <0.5 at a cutoff value of plateletcrit of 0.25. Conclusions: In RA patients, hematological indices and ratios could serve as a QoL assessment tool, particularly plateletcrit, as higher plateletcrit (≥0.25) were found to negatively impact the physical health, psychological, and environmental domains.