Background Diagnosis of a surgical-site infection (SSI) in dermatological surgery can be based entirely on a subjective assessment, according to the fourth criterion of the most common definition of an SSI, which was established by the US Centers for Disease Control and Prevention. Objectives To investigate the interobserver agreement between dermatologists in their diagnosis of SSI of dermatosurgical wounds. Methods An international electronic photographic survey with eight photographs of wounds 1 week after full-thickness skin grafting (FTSG) was sent to dermatologists. All wounds were assessed in terms of visual criteria beforehand. Data collected from respondents included physician characteristics and experience, and SSI assessments of all wounds. Results In total, 393 dermatologists from 27 countries enrolled. Most respondents were from the U.S.A. (25%), followed by Sweden (24%) and the U.K. (13%). There was only a slight interobserver agreement on SSI suspicion (kappa = 0 center dot 19). SSI suspicion was lower for male physicians (P = 0 center dot 03), board-certified dermatologists (P = 0 center dot 001), physicians regularly assessing surgical wounds (P = 0 center dot 03) and physicians performing FTSG (P < 0 center dot 001). Swedish physicians diagnosed more SSIs than U.S. physicians (P = 0 center dot 002). Erythema was more common in cases with higher SSI suspicion. Conclusions This study reveals broad inter-rater variability in the diagnosis of SSI, illustrating the need for novel objective diagnostic methods that can better capture the variables that constitute an SSI.