They found that teens in serious sexual relationships and those who abstained from sex were similar in their grade-point averages.
Sexually active teens in serious relationships were also not more likely to have disciplinary problems in school.
The study also found that teenagers who had casual sexual relationships fared worse than those who had not had sex at all. Students who participated in flings received lower grades and had more school-related problems.
A recent survey found nearly half of high school students reported having sex last year.
The Associated Press contributed to this report.