The main objective of the present study was to examine the role of motivation and action orientation in forming spontaneous (i.e., without specific instruction or manipulation) implementation intentions for a healthy diet goal. We hypothesized that (1) the adoption of a diet goal would be determined by (either intrinsic or extrinsic) motivation only whereas, (2) forming implementation intentions would be determined by intrinsic motivation and (either low or high) action orientation. These hypotheses were addressed in a sample of 142 normal weight subjects who were concerned about their dietary habits. Primary outcomes were goal intentions and implementation intentions. Our hypothesis regarding the prediction of goal intentions was confirmed whereas results relating to the prediction of implementation intentions demonstrated that intrinsic motivation and low (but not high) action orientation proved significant predictors of intentions to implement a healthy diet goal. These findings suggest that self-regulatory skills as assessed by the concept of action orientation may relate to short-term strategies of initiating behavior change only. Copyright © 2008 John Wiley & Sons, Ltd.