This study examines the information content of interim financial statements, especially interim earnings, of listed Finnish firms. The information content of the interim earnings announcement as such, and the level of association between returns and interim earnings during the interim earnings period will be studied separately. The motivation for the study is twofold: (a) in Finland there is a lack of studies focusing on interim financial statements, and (b) the statutory interim financial statement components offer a possibility to specify a priori a permanent and a transitory component to interim earnings. The assumption is that, compared to transitory change, permanent changes in earnings have a greater association with returns. The event part of the study shows that the announcement of interim financial statements contains some information. In the association part of the study the association between returns and interim earnings at the single firm level is rather low. However, a greater association between returns and interim earnings was obtained by constructing portfolios of two to six firms according to a returns or earnings-based ranking. In addition, the results suggested the existence of a slight lead-lag relation when firm´s market value is used as a deflator.