Aim: The primary aim was to examine differences in baseline symptom expression, neurocognition, social cognition and psychosocial functioning between Dutch, first-generation immigrants and second-generation immigrants with a first-episode psychosis (FEP). The secondary aim was to examine functional and symptomatic change and between-group differences at 12-months follow-up. Associations between migration, baseline characteristics and outcome were explored. Methods: Forty-six Dutch, 56second-generation- and 60 first-generation immigrant patients completed baseline measures for 6 symptom dimensions (positive symptoms, negative symptoms, neurocognitive functioning, social cognitive functioning, excitement and emotional distress) and 5 domains of psychosocial functioning (general functioning, work and study, relationships, self-care and disturbing behaviour). Functioning and psychotic symptoms were assessed at baseline and 12-months follow-up. ANCOVA and t tests were used to assess between-group differences. General linear models were used to explore within-group differences. Backward-regression was used to explore predictors of outcome. Results: Levels of positive symptoms, excitement and emotional distress did not differ between groups at baseline or follow-up. Dutch patients had lower levels of negative symptoms than both immigrant groups at follow-up. On neurocognition and social cognition, Dutch performed better than second-generation immigrants, who in turn performed better than first-generation immigrants. Psychosocial functioning across all domains at baseline and at 12-months follow-up was similar across groups. Baseline levels of general psychosocial functioning and income were the strongest predictors of outcome at follow-up. Conclusions: Psychosocial functioning and symptom profiles are comparable between Dutch, first-generation immigrant and second-generation immigrant FEP patients, excluding neurocognitive and social cognitive deficits. A range of baseline characteristics predicted outcome.