The goal of this research was to investigate the effects of aerobic exercises (AEs) on ventilatory functions, chest expansion, exercise capacity, and quality of life in women with rheumatoid arthritis. A total of 66 women diagnosed with rheumatoid arthritis were assigned randomly to two groups of the same size. Over a period of 12 weeks, the AE group engaged in aerobic workouts of moderate-to-high intensity, three times per week, along with diaphragmatic breathing exercises, whereas the control group only received diaphragmatic breathing exercises. Outcome measures included forced vital capacity, forced expiratory volume in the first second, total lung capacity, upper and lower chest expansions, maximal oxygen consumption, physical component score, and mental component score components of the 12-item Short Form Health Survey. Compared with baseline measurements, the AE and control groups exhibited substantial improvements in all outcomes by the completion of the trial (p < .05). Compared with the controls, the AE group revealed substantial increases in forced vital capacity (10.2% vs. 4.8%, p = .02), forced expiratory volume in the first second (8.9% vs. 4.07%, p = .01), total lung capacity (10.86% vs. 5.35%, p = .008), upper chest expansion (21.37% vs. 11.71%, p = .04), lower chest expansion (28.33% vs. 10.63%, p = .03), maximal oxygen consumption (30.7% vs. 15.01%, p = .01), physical component score (17.68% vs. 11.04%, p = .003), and mental component score (25.65% vs. 13.21%, p = .01). In women with rheumatoid arthritis, the addition of moderate-to-high AE to diaphragmatic breathing exercises could improve ventilatory functions, chest expansion, exercise capacity, and quality of life.