Complete findings for this study are in the journal "Pediatrics."
University of Southern California researchers studied the "sexting" habits of more than 1,800 Los Angeles high school students.
They found, of those with access to a cellphone, 15 percent engaged in sexting, and 54 percent said they knew someone who sent a "sext."
But, teens who had sexted were more likely to report being sexually active, and were more likely to have had unprotected sex, compared to those who did not sext.
Researchers say parents and pediatricians may want to bring the topic up, especially when discussing sexual activity.