Background: psychological alienation and Social support networks affect the elderly's meaning in life. Strong social connections provide emotional support, companionship, and a sense of belonging. Psychological alienation, which causes feelings of isolation and disengagement, might raise stress, depression, and life dissatisfaction in older people. Aim: The study aimed to compare the perceived meaning in life, psychological alienation and social support in community-dwelling and institutionalized elderly. Design: descriptive, comparative design was utilized. Sample: a purposive sample of 100 institutionalized and 100 community-dwelling elderly people was recruited.  Sitting: institutionalized sample from three residential homes. Non- institutionalized sample was taken from the waiting areas of governmental banks and Egyptian post offices affiliated to Cairo governorate. Tools: Socio demographic Data Profile, Meaning in life Questionnaire, Dean's alienation scale& Multidimensional Scale of Perceived Social Support scale. Results: Statistically significant differences between community-dwelling elderly group and institutionalized elderly group regarding psychological alienation and social support. While there was no statistically significant difference between both groups regarding meaning in life. Social support was statistically significant correlated negatively with alienation and positively with meaning in life in both groups. Additionally negative correlation between alienation and meaning in life in community dwelling group was reported. However no statistically significant correlation was found between alienation and meaning in life among the institutionalized group. Conclusion:  the institutionalized elderly individuals experienced higher levels of psychological alienation and lower levels of social support compared to the community-dwelling group. However, the two groups experienced the same level of perceived MIL. Recommendation more emphasis should focus on creating positive social support atmosphere and encouraging elderly to search for or maintain a meaningful life.