The COVID-19 pandemic does not affected only physical but also mental health and socioeconomic part. The social distancing, social quarantine, school from home, and work from becomes a new normal these days. Being adolescence, the above conditions may be challenging due to their developmental milestones. Therefore, this brief report aimed to preliminary identify proportion of adolescents' emotional and behavior problems and several factors related to it during COVID-19 pandemic in Indonesia. The findings might raise some understanding of youth mental well-being and programs that can be applied in schools and community in general to overcome the issues. The study was designed as cross sectional and used online survey that started on April 2020. During April 15-May 10, 2020, there were 113 adolescents participated on this survey. Strength and Difficulties Questionnaire (SDQ) 11-17 years old was used to assess adolescent emotional and behavior problems; and specific life experience questionnaire was designed to collect other independents variables (Cronbach's α = 0.75). All participants fulfilled the online informed consent before they started to complete the questionnaire. All data was analyzed by using SPSS version 20 for Mac. The average age of research subjects were 14.07 (2.18) years old; 98.2% was school from home. There was 14.2% of the total research subject at risk on total difficulties problems; 38.1% of adolescent was at risk on peer-relationship problems, 28.3% at risk on pro-social behavior problems, 15% at risk on conduct behavior and 10.6% at risk on emotional problems. The number of adolescent that perceived worse to significantly worse self-mental well-being prior COVID-19 increased during COVID-19 pandemic in Indonesia ( < 0.05). There was significantly association between having mental health information and conduct behavior (OR = 10.34, 95%CI = 1.27-78.86); Subjective anxiety due to COVID-19 pandemic and pro-social behavior problems (OR = 2.37, 95% CI = 1.00-5.63), parental support and total difficulties (OR = 0.09, 95% CI = 0.14-0.60) and pro-social behavior problems (OR = 0.09, 95% CI = 0.01-0.82); friends support during COVID-19 pandemic and conduct behavior (OR = 0.20, 95% CI = 0.04-1.00) and pro-social behavior problems (OR = 0.14, 95% CI = 0.02-0.75). To be concluded, during phase 1 and 2 COVID-19 pandemic and school closures in Indonesia, adolescents were at risk for having emotional and behavior problems. Therefore, maintain clear mental health information, keep them on connection with school by designing an optimal tele-education, tele-consultation, and virtual activity programs to accommodate adolescents' biopsychosocial needs in the near future.