Background: In addition to playing significant role in the decline of physiological functions and the onset of depression, frailty is involved in a vicious circle with depression that has serious physical and mental impacts on sufferers. Furthermore, elderly people with frailty are less mobile, at increased risk of dissociative interpersonal relationships, and prone to develop a sense of loneliness, which also pose health threats. Purposes: This study was designed to explore the improvement effects of an aromatherapy intervention on depression and loneliness in the elderly with frailty living in daycare centers. Method: This study adopted a quasi-experimental, pre-and-post-test research design. This study enrolled 82 frail elderly people from six daycare centers in Taipei City as the research subjects. The subjects in the experimental group received aromatherapy twice a week for 30 minutes each session for four weeks. The researcher guided the experimental group in a small group setting to perform self-massage on the face and hands with lavender essential oil. The control group was guided in the same self-massage routine using pure base oil. Results: Depression in the subjects was found to be positively correlated with degree of frailty. After the intervention, depression and loneliness was found to have decreased significantly in the experimental group (p <.05). Conclusions: The findings support the beneficial effects of aromatherapy interventions on depression and loneliness in the elderly with frailty living in daycare centers without adverse reactions. Aromatherapy may be used to improve depression and loneliness in elderly people with frailty.