Loneliness refers to the subjective state of negative feelings associated with perceived social isolation, lower lever of contacts with other people than that desired or the abscence of a particularly desired person. Widowhood that is the loss of a spouse is one of the most stressful life events married older adults experience. Widowhood brings changes on many fields, so the widow or widower must face changes of the psychological, economical and social aspects. Social support is defined as the concept in which a person experiences that she is loved, respected, valued and cared for. Social support has an important role in reducing the feeling of loneliness in the elderly. This paper reviews the loneliness that is how to understand loneliness, how to spot loneliness and the consequences of loneliness. This paper reviews the widowhood, the consequences of widowhood and the importance of social support during widowhood. This paper also reviews the adjustment of elderly to loneliness and what are the ways to help a lonely elderly person.