Osteoarthritis is the most common disease among the elderly population and is expected to be one of the leading causes of physical disability worldwide. Our objective was to compare the effects of physiotherapeutic interventions versus pharmacological treatment on outcomes and quality of life in elderly patients with osteoarthritis. This cohort study was conducted on 119 elderly individuals aged 60 to 95 years (58.8% women) from the YUYAQ nursing home. Two groups were divided: the intervention group (58 individuals–48.7%) received a two-month physiotherapy program, and the control group (61–51.5%) received exclusive use of anti-inflammatories. Between the intervention and control groups, we observed significant improvements (all p < 0.001) regarding pain (93.1% vs. 60.75%), stiffness (94.8% vs. 62.3%), and functional capacity (96.6% vs. 68.9%). Additionally, the intervention group showed better quality of life than the control group (13.81 vs. 41.38, p < 0.001). Quality of life improvement and clinical outcomes in the treatment group significantly improved in all areas of osteoarthritis, primarily in hip, spine, and knee osteoarthritis (p < 0.001). In conclusion, the physiotherapy intervention improved pain, stiffness, functional capacity, and quality of life in elderly patients with osteoarthritis after two months of treatment. Transitioning from pharmacological treatment to physiotherapeutic treatment in patients with osteoarthritis may substantially improve quality of life and disease symptomatology, but long-term studies are needed.