The obsessive-compulsive manifestations course was assessed with the Leyton obsessional inventory-child version survey (LOI-CV) in a 3-year prospective study, using a non-clinical sample. From an initial sample of 1,514 school-age children who underwent symptoms screening for obsessive-compulsive, anxiety and depression, 562 subjects (risk group/without risk group) were re-assessed in the 2nd phase and 242 subjects were monitored after 3 years. LOI-CV scores significantly decreased over time independently of age and gender. The prevalence, persistence and incidence for two levels of severity of obsessive–compulsive manifestations ranged between 4.8-30.4%, 9.3-28.4% and 1.1-14.4%, respectively. 34.6-64.5% of obsessive-compulsive symptomatology was predicted by anxiety, depressive and obsessive-compulsive symptoms. For the obsessiveness (less severe form of obsessive-compulsive manifestations), the depressive symptoms were not predictors. Gender and socioeconomic status were not related with obsessive-compulsive manifestations. These data support a substantial continuity of the obsessive-compulsive manifestations and the existence of different levels of severity within the obsessive-compulsive spectrum.