This randomized controlled experimental study was conducted to determine the effect of inhaled aromatherapy on the sleep quality and fatigue level of the institutionalized elderly. The sample of the study consisted of a total of 59 elderly individuals (30 in the intervention group and 29 in the control group) who met the inclusion criteria and agreed to participate in the study. Aromatherapy (lavender oil) inhalation was administered to individuals in the intervention group half hour before their sleep every day for a month in accordance with aromatherapy protocol. No administration was applied to the control group. The data were collected using the Elderly Description Form, Pittsburgh Sleep Quality Index, and Fatigue Severity Scale. Forms were completed in the beginning of administration and in the follow-up at the end of 4 weeks (baseline and last follow-up). In the study, it was determined that aromatherapy administration improved sleep quality (P < .001) and decreased fatigue severity in the elderly (P < .05). The study should be replicated in a different group.