Introduction: Acute Respiratory Infection (ARI) is the most common cause of mortality in ‎children under five years of age. Its treatment and care costs a lot and if left untreated, can ‎cause irreversible side effects. Prevention is more important than treatment and for prevention, ‎identifying predictive factors are essential.‎ Objective: This study was conducted to determine the personal, familial and social ‎characteristics of infants with ARI.‎ Methods: The present study is a descriptive study which covered past two weeks in ‎‏27‏‎ Health ‎centers in Rasht city. Sample included ‎‏375‏‎ infants up to ‎‏12‏‎ months of age which consisted ‎‏0‏‎.‎‏7%‏‎ of all infants in Rasht and were chosen by simple sampling. Parents were asked about ‎their infants regarding ARI in past ‎‏2‏‎ weeks and finally ‎‏149‏‎ ill infants and ‎‏220‏‎ healthy children ‎were assessed. The data collection tool included a questionnaire and data were analyzed ‎through Chi-Square and Logit by soft ware SPSS‏10‏‎.‎ Results: Findings showed that there was a significant relationship between ARI and personal, ‎characteristics such as age (OR=‎‏375/1‏‎, P=‎‏002/0‏‎), order of children (P=‎‏011/0‏‎), familial ‎characteristics such as mothers , age under ‎‏25‏‎ (OR=‎‏292/0‏‎), parents , education (P=‎‏035/0‏‎, ‎P=‎‏028/0‏‎), mean monthly income under ‎‏100/000‏‎ Tomans (OR=‎‏1/689‏‎ , P=‎‏0/043‏‎), residential ‎housing(p= ‎‏0/024‏‎) , smoking more than ‎‏10‏‎ cigarettes daily by parents (P=‎‏0/036‏‎ , OR= ‎‏3/038‏‎), ‎one of house residents with ARI(P=‎‏0/000‏‎) , and social characteristics such as other children in ‎schools or day care centers(P=‎‏0/047‏‎ , P=‎‏0/015‏‎) , no medical insurance (P=‎‏0/044‏‎) and living in ‎houses smaller than ‎‏70‏‎ square meters with family member more than ‎‏4‏‎(P=‎‏0/025‏‎).‎ Conclusion: In order to decrease ARI in infants, their exposure to others must be limited in ‎second six months of life, and also no more than four people in the house, satisfactory ‎economic condition, educated parents, healthy smoking, knowledge of ARI transmission, and ‎proper house square meters with number of family members must be acknowledged.‎