Background information: Condoms being the most effective preventive intervention against STIs, including HIV, to study the factors associated with its use among out-of-school youth aged 15-24 years who are mostly affected due to lack of information on condoms is important in designing and monitoring intervention programmes to control the spread of the epidemic in that particular age group. Objectives: The broad objective of this study was to determine the factors associated with condom use among sexually experienced out-of-school youth aged 15-24 years old in Kinondoni municipality, Dar es Salaam. Methods: A cross sectional analytical study which used both qualitative and quantitative methods was used. It involved a total of 186 males and 162 females out-of-school youth aged 15-24 years in selected wards in Kinondoni municipality. Multistage sampling and convenience sampling methods were used. Face to face interviews using a structured questionnaire, 8 In-depth interviews using an interview guide and 2 focus group discussions using a focus group discussion guide were conducted. The tools were translated from English to Kiswahili and pre-tested in Ilala municipality. Quantitative data were analyzed using SPSS program version 16.0 whereby qualitative data were analyzed using thematic framework method. Results: Males and those who were older (20-24 years) were more likely to use condoms. Only 31.0% of respondents reported to use condoms consistently. Sex under the influence of alcohol was significantly associated with not using condom (p = 0.008). Occasional intercourse in the last 3 months was found to be associated with not using condom (p< 0.001). Positive beliefs were reported but also negative beliefs (psychosocial barriers) were reported. Freedom to discuss condom use had a significant influence on condom use behavior (p< 0.001). Conclusion: Overall, condom use was low and youth reported to use condoms inconsistently. Programmes dealing with youth should find ways to address the issue of inconsistent use of condoms among out-of-school youth. Key Words: Condom use; Out-of-school youth; Kinondoni municipality.