Introduction: Undernutrition among adolescent girls is an important concern due to their rapid growth velocity that requires adequate intake of energy and nutrients. This study compared intake adequacy and dietary diversity between adolescent public schoolgirls from slum areas in Central Jakarta who had normal and poor nutritional status. Methods: A total of 220 eligible girls aged 14–18 years were recruited, with an equal proportion in the normal group (NG) [-1 to +1 SD body mass index-for-age z-score (BAZ)], and undernutrition group (UG) (BAZ < -1SD). Dietary intake was assessed using two non-consecutive 24-hour recalls. Dietary diversity scores (DDS) were determined with reference to the intake of 13 food groups with a minimum daily intake of 15 gram/food group. Receiver operating curve analysis was performed to obtain the DDS cut-off. The Mann–Whitney test was performed to compare DDS between the NG and UG. Logistic regression analysis was conducted to examine the likelihood of potential factors in predicting nutritional status outcome. Results: Overall, almost half of the girls’ daily food intake showed low dietary diversity based on DDS cut-off <5, with no significant difference between NG and UG adolescents. Protein intake inadequacy showed significant unlikelihood of a NG outcome (OR=0.4; 95% CI: 0.2-0.8), while low socioeconomic status (SES) showed a strong likelihood of an UG (OR=2.7; 95% CI: 1.3-5.5) compared to high SES. Conclusion: Low dietary intake and DDS were common among adolescent schoolgirls in slum areas in Jakarta. Nutrition interventions promoting appropriate dietary intake among adolescent girls are recommended.