The present review refers to studies published in leading international research journals in 2003. It gives priority to published research on learning, teaching and policy in respect of second, modern foreign or additional languages. The aim is not simply to describe or summarise the studies which have been selected for comment, but rather to identify key features which seem to be significant. Since in each case only a few brief and not fully representative words can be devoted to any one article, a further aim of the review is of course to point readers in the direction of the original articles themselves. As usual, I have broken the review down into a number of key themes, beginning this year with Affective Factors. However, this does not imply that an article deals exclusively with the theme into which I have assigned it. An article appearing in the theme of Acquisition and Learning for example will in many cases have relevance to other themes such as Proficiency, Teaching, Strategies or Curriculum. As in previous years reference is made to the abstracts. Thus, MacIntyre, Baker, Clément & Donovan (2003: 03-463) refers to an article by these four authors published in 2003 and reflected in the 2003 series of this journal as abstract 463.