Cellular phones provide a means for parents to monitor and request information about whereabouts, associates, and current activities from adolescents. Simultaneously, adolescents can communicate with parents to inform them of activities and to solicit support or they can also choose to nondisclose. The frequency, duration, and nature of calls may relate to parents' and to adolescents' perceptions of truthfulness and family relationships. 196 dyads (13% father-son, 11% father-daughter, 30% mother-son, and 46% mother-daughter) completed a questionnaire indicating cell phone use, their truthfulness of activities, the nature of their calls to one another, and family relationships. The parents were, on average, 45.38 years old (SD = 6.35) and were 83% Euroamerican, 9% Asian American, 3% Latino, 3% African American, 2% Mixed ethnicity, and 1% American Indian. The adolescents were, on average, 16.25 years old (SD = 1.17) and were 77% Euroamerican, 9% Asian American, 4% Latino, 3% African American, 8% Mixed ethnicity, and 0.5% American Indian. Correlational analyses revealed that parents who called more frequently reported less truthfulness when speaking to their adolescents via cell phone. Greater frequency in parental calls also was associated with less adolescent-reported truthfulness. From multiple regression analyses, for parents, calls when upset were associated with less parental knowledge and poorer family relations. For adolescents, the same was true; however, adolescents who made calls seeking social support and to ask and confer with parents reported greater perceived parental knowledge and better family relationships.