Evidence indicates that migrant and ethnic minority groups have an elevated risk of psychosis in a number of countries. Social disadvantage is one of the hypotheses put forward to explain these findings. The aim of this study is to investigate main effects, association and synergism between social disadvantage and migration on odds of psychotic experiences. We collected information on social disadvantage and migration from 332 patients and from 301 controls recruited from the local population in South London. Two indicators of social disadvantage in childhood and six indicators of social disadvantage in adulthood were analyzed. We found evidence that the odds of reporting psychotic experience were higher in those who experienced social disadvantage in childhood (OR= 2.88, 95% CI 2.03-4.06), social disadvantage in adulthood (OR= 9.06, 95% CI 5.21–15.74) and migration (OR = 1.46, 95% CI 1.05–2.02). When both social disadvantage and migration were considered together, the association with psychosis was slightly higher for social disadvantage in childhood and migration (OR 3.46, 95% CI 2.12–5.62) and social disadvantage in adulthood and migration (OR 9.10, 95% CI 4.63-17.86). Migrant cases were not more likely than non-migrant cases to report social disadvantage (p = 0.71) and no evidence of an additive interaction between migration and social disadvantage was found (ICR 0.32 95% CI -4.04–4.69). Preliminary results support the hypothesis that the association between social disadvantage and psychosis is independent of migration status.