Background: There is increasing evidence that parental determinants of offspring early life development begin well before pregnancy. Objectives: We established the Victorian Intergenerational Health Cohort Study (VIHCS) to examine the contributions of parental mental health, substance use and socioeconomic characteristics before pregnancy to child emotional, physical, social, and cognitive development. Population: Men and women were recruited from the Victorian Adolescent Health Cohort (VAHCS), an existing cohort study beginning in 1992 that assessed a representative sample of 1943 secondary school students in Victoria, Australia, repeatedly from adolescence (Wave 1, mean age 14 years) to adulthood (Wave 10, mean age 35 years). Methods: VAHCS participants with children born between 2006 and 2013 were recruited to VIHCS, and invited to participate during trimester three, at 2 months postpartum, and one year postpartum. Parental mental health, substance use and socioeconomic characteristics were assessed repeatedly throughout; infant characteristics were assessed postnatally and in infancy. Data will be supplemented by linkage to routine datasets. A further follow-up is underway as children reach eight years of age. Preliminary results: Of the 1307 infants born to VAHCS participants between 2006 and 2013, 1030 were recruited to VIHCS. At VIHCS study entry, 18% of recruited parents had 4 preconception common mental disorder in adolescence and young adulthood, 18% smoked daily in adolescence and young adulthood, and 6% had not completed high school. Half of VIHCS infants were female (48%), 4% were from multiple births, and 7% were preterm (<37 weeks gestation). Conclusions: VIHCS is a prospective cohort of 1030 children with up to nine waves of preconception parental data, and three waves of perinatal parental and infant data. These will allow examination of continuities of parental health and health risks from the decades before pregnancy to offspring childhood, and the contributions of exposures before pregnancy to offspring outcomes in childhood.