BACKGROUND/OBJECTIVES: This study aimed to examine the food security status of urban poor adolescents and its association with diet quality. SUBJECTS/METHODS: A cross-sectional survey was conducted among 188 adolescents aged 13–18 yrs living in Kuala Lumpur, Malaysia. Household food insecurity and dietary intake data were collected using the Radimer/Cornell hunger and food insecurity instrument and 2-day 24-h dietary recalls, respectively. Diet quality was determined using the Malaysian Healthy Eating Index (HEI). Weight and height were measured and body mass index-for-age, as well as height-for-age z scores were calculated. RESULTS: The present study revealed that 47.9% of the adolescents experienced household food insecurity, 24.5% experienced individual food insecurity, 18.6% household food security, and 9.0% child hunger. The mean score of diet quality was 56.83 ± 10.09, with a significantly lower HEI score among food insecure adolescents (household food insecure, individual food insecure, and child hunger) than household food secure adolescents (P = 0.001). The differences between food secure and food insecure households were found to be significant for energy (P = 0.001) and nutrients including proteins (P = 0.006), carbohydrates (P = 0.005), dietary fiber (P = 0.001), folate (P < 0.001), and vitamin C (P = 0.006). The multiple linear regression showed that adolescents who experienced food insecurity (β = −0.328; P = 0.003) were found to be significantly associated with poor diet quality (F = 2.726; P < 0.01), wherein 13.3% of the variation in the diet quality was explained by the food security status. CONCLUSIONS Experiencing food insecurity contributed to poor diet quality among urban poor adolescents. Further longitudinal studies are needed to comprehensively understand this association to improve food insecurity and diet quality among urban poor communities.