Background: Poor symptom outcome remains a challenge in psychosis: At least 50% of first-episode patients continue to have positive and/or negative symptoms after ten years. Objective: To investigate rates, early predictors and early symptom progression of long-term non-remitted psychosis in an early detection study. Methods: Symptomatic remission according to new international criteria was assessed in 174 patients at ten-year follow-up. Remitted and non-remitted patients were compared on early symptom progression, and logistic regression was applied to predict non-remission. Results: At ten years, 50% of patients were in symptomatic remission. Non-remission was predicted by positive symptoms at inclusion and during the first year of treatment. Of individual symptoms only hallucinations were significantly predictive of ten-year non-remission. Early symptom differences were not reflected by differences in treatment. Conclusions: Long-term symptomatic non-remission is associated with early positive symptoms. More assertive intervention may be needed in patients who do not respond robustly in the first year of treatment, whether or not they have been detected "early".