Frailty syndrome is one of the most important problems of the aging population. Various pathophysiological factors constitute the pathophysiology of the syndrome, including dysregulation of inflammatory processes, oxidative stress, mitochondrial dysfunction, and cellular aging. Sociodemographic characteristics, psychological conditions, nutritional status, lack of physical activity, and existing comorbidities are factors that affect frailty. Omega-3 polyunsaturated fatty acid (PUFA) is known to have beneficial effects in the elderly with acute or chronic diseases due to its anti-inflammatory effect. The purpose of this review is to examine and evaluate the evidence for the role of dietary or supplemental omega-3 PUFA in muscle mass and muscle strength, inflammatory biomarkers, and functional capacity in elderly individuals. Studies support that omega-3 PUFA may improve the course of the syndrome in pre-frailty older adults. The effects of dietary or supplemental omega-3 PUFA in frail elderly are controversial. All studies emphasize the importance of routinely controlling nutritional status and making the necessary dietary interventions to prevent the development of sarcopenia and frailty.