Oro-facial cleft (OFC) is one of the most common congenital anomalies at birth and requires long-term multidisciplinary treatment. The incidence is higher in New Zealand (1 in 565) than generally quoted rates (1 in 700) and much of this is due to the high rate of cleft palate alone in the Maori population. To date there has been little advancement in identifying environmental or genetic factors that may lead to prevention of OFC. The proposed case-control study seeks to identify environmental and genetic factors and gene by environment interactions associated with OFC. The project has strong links with the funded UK Cleft Collective and also with proposed studies in Australia and Vietnam, providing opportunities for pooled analyses, with greater statistical power and diversity of populations. Thus the project has the potential to identify factors which could lead to public health interventions and potentially prevention of oro-facial cleft.