This article describes the general findings of the initial cross-sectional stage of a prospective follow-up study of all first episodes of schizophrenia that occurred in the Autonomous Community of Cantabria over a 2-year period and that established contact with any mental health service. The project comprises: i) a 2-year cross-sectional stage, in which the sample was gathered and studied with structured psychiatric instruments such as the Present State Examination and the Scales for the Assessment of Negative and Positive Symptoms (SANS and SAPS), and; ii) a continuous follow-up. We detected, in the risk age ranged of 15-54 years, an incidence of 1.9 per 10,000 inhabitants per year for schizophrenia and of 1.3 per 10,000 inhabitants per year for the S+ CATEGO diagnosis, without any significant gender difference of morbidity. The mean age for the total schizophrenic population was 26 years, being significantly higher in women than in men. In contrast with what happens with marital status, type of household or urban/rural way of life, there was no gender difference in relation to the other sociodemographic variables. The way in which nosological and clinical variables are associated with first episodes of schizophrenia was also examined in this study. We found that 75% of patients reached a maximum CATEGO-ID level, 71% received a S+ CATEGO diagnosis, 59% presented first-rank symptoms of schizophrenia and that the percentage of a schizophrenic negative syndrome, as identified by the SANS and SAPS, was very low.(ABSTRACT TRUNCATED AT 250 WORDS)