 Mothers of an infant are much less likely to exercise regularly compared with women who have older children or no children. This low level of physical activity PA contributes to postpartum weight retention which can predict levels of obesity up to 15 years later. Ethnic minorities have higher rates of inactivity and gain more weight following childbirth, which places them at increased risk for cancer and other chronic diseases consistent with known health disparities for these ethnic groups. Few PA interventions have been designed to increase PA in women with an infant, especially ethnic minority women. This study will test the efficacy of a tailored intervention to increase and maintain PA in a multiethnic population of 268 young, healthy postpartum women living in Hawaii. Women will be recruited from health care settings, motherbaby support groups, and from the media campaignsTV, radio, newspaper, parents magazines. Subjects will be randomly assigned to either a tailored postpartum counseling intervention on PA or standard care for PA. The tailored PA intervention will address key personal, social, and environmental factors derived from Social Cognitive Theory and the Transtheoretical Model. Also, multimodal contacts telephone, e-mail, website will be used to deliver theoretically-derived, culturally sensitive PA counseling,behavioral skills training e.g., goal setting, and local resourcesreferrals tailored to a mother with an infant. The standard care condition receives American Heart AssociationAmerican College of Sports Medicine print materialse-mails and referral to PA internet resources. 