We introduce a new measure of sub-clinical self-harm tendencies, the Voodoo Doll Self-Injury Task (VDSIT). In this computer task, participants virtually stick a number of sharp pins in a doll that represents themselves. Across five community and undergraduate samples who were not recruited based on their self-harm history or risk (total N = 1,289), VDSIT scores were higher among participants with histories of actual self-injury and were positively correlated with state and trait level motivations to self-harm. VDSIT scores did not correspond to tendencies to harm others, showed sensitivity to experimental manipulations that increase self-harm tendencies, and were positively correlated with established risk factors for self-harm (e.g., depression). The VDSIT did not, on average, elicit significant distress from participants during or after the task, even among participants who had previously engaged in self-harm. Whereas the clinical utility of this measure remains unexamined, these findings provide initial support for the VDSIT’s sub-clinical validity, which can help researchers accurately, economically, and rapidly measure state and trait level self-harm tendencies using both correlational and experimental designs.