Research on pre-task planning has shown that planning has beneficial effects on learners' subsequent language output. However, to date most of this research has focused on solitary rather than group planning. Furthermore, very few studies have investigated what actually happens during the planning time. This study, conducted in an EFL class in Vietnam, investigated the nature and impact of group planning on learners' subsequent individual oral presentations. The learners (n = 17) worked in small groups preparing for oral presentations. At the end of the planning session, two learners from each group were randomly selected to give presentations. All group work and individual presentations were audio recorded and teacher observation notes were collected. Transcribed oral data were coded for idea units and language related episodes as well as salient features of group interaction. The study found that group planning dealt with the content rather than the language of presentations. Using a matching procedure, the study found that most of the ideas presented were generated during the planning time. However, there were variations between the groups. The group that seemed to be the most interactive and that focused on both content and language was a group composed of mixed proficiency learners. (Contains 2 figures, 5 tables, and 2 notes.)