A cross-sectional study was conducted in five slums of Dhaka city. The study population was all adult women of reproductive age having an infant aged less than one year with a view to assessing the prevalence of Acute Respiratory Infections (ARIs) among the slum infants and also to identify the factors responsible for it. A total of 1,008 mothers were interviewed. Among them, 927 had children aged 0-12 months. Mothers with live infants (927) were asked if their children had any disease during the two weeks prior to the interview. Respiratory infection was the highest among the prevalent diseases (ARI 72%, diarrhoeal diseases 28%, measles 4% and others 4%). So, an emphasis was given in this regard. Out of 228 ARI cases, percentage of mild (78%) and severe ARI (11%) were present in children aged less than 6 months, whereas moderate ARI (23%) was higher in 6 months and above age groups. The variation was statistically significant between the two age groups (p<0.05). But there was no significant difference in ARI by sex (p>0.05). In logistic analysis, maternal age below 20 years, working mothers, low housing and socio-economic index, no household possession, no access to piped water and infant's age above 6 months appeared to be significant predictors of ARIs. The risk of acquiring ARI was 3.33 times higher in low socio-economic index, 3 times in no access to piped water, 2.39 times in low housing index, 1.9 times in mother's age below 20 years, 1.85 times in infant's age above 6 months, 1.69 times in working mothers. On the other hand, household possessions had protective effects on ARIs. The study provides important information for policy makers regarding the prevention of ARI among the children of the slum dwellers.