Ballet dancers need to constantly improve their performance. Several studies show that an internal focus (on body movements) leads to inferior motor performance relative to an external focus of attention (on the movement effects), but the majority of dancers usually adopt an internal focus. It is not clear if the benefits of an external focus are relevant for form-based tasks performed in a ballet. Purpose: Test whether an imagined external focus of attention can improve ballet dancers' performance of a form-based task, the "en dehors" double "pirouette" (EDDP). Method: 23 experienced amateurs and 17 professional dancers between 18 and 35 years old performed three EDDP under each of three attentional focus instruction conditions (No Focus, Internal, Imagined External). Order of presentation of Internal and Imagined External focus instructions was blocked and balanced across participants. Movement quality was assessed by three experts with a customized observational scale. Movement kinematics were measured by the angle of inclination of the trunk and inclination of the rotation axis with respect to the global vertical during the EDDP. Results: Movement quality and trunk inclination were significantly different between amateurs and professionals, but the rotation axis inclination was not. No quantitative or qualitative effects of focus were found for the performance of the EDDP across focus conditions. Conclusions: There appears to be no differential effects of using an internal or imagined external focus on the immediate performance of the EDDP for amateur and professional ballet dancers. Personal and task factors might account for the lack of effects.