Recruiting adolescents to participate in research studies, with or without a clinical intervention, is challenging. This is especially true for ethnic minority groups and for pediatric populations at higher risk, such as those with obesity. Identifying effective recruitment and retention methods for these populations is vital to successful recruitment. This study discusses strategies and considerations used to recruit and retain 342 adolescents, including 41% ethnic minority and 50% with overweight or obesity, into a 2-year observational cohort study. Several strategies were used throughout the study’s 24-month recruitment timeline. These included no cost advertisements, community outreach, paid media, earned media, and internal recruitment methods. These strategies were implemented by a team of recruiters, project managers, and research specialists. Retention efforts included regular follow-up surveys, phone calls, and emails to keep contact information up-to-date in preparation for scheduling of Year 2 assessment visits. A total of 823 parents/guardians phone screened over 26 months, and 342 adolescents aged 10 to 16 years were enrolled into the study. The institution’s email listserv, consisting of former participants and attendees of the research center’s outreach events, resulted in the largest percentage of enrolled participants (~30%). Social media (~21%) and word-of-mouth (~13%) were the next leading strategies. For retention, emails to continue engagement and regular follow-up contacts have been successful as 86% of participants have returned for Year 2 visits as of July 2019. A variety of recruitment methods were necessary to reach the target population and complete enrollment. Efforts must also be put into participant retention to complete as many enrolled participants as possible.