Specialist search dogs are relied upon by law enforcement agencies worldwide to provide assistance in locating a variety of target substances, such as explosives, flammable materials, currency, live and dead bodies, and land mines. Given the extensive skills and training necessary to carrying out the job of a specialist search dog, only a small minority of dogs will possess the characteristics necessary to attain the position of specialist search dog. Selection procedures for these canines are tough, however there is little documented literature that describes the characteristics that constitute a good specialist search dog. In an effort to rectify this literature gap, the authors designed a questionnaire that examined the characteristics that search dog trainers and handlers consider most desirable in a potential search dog. The design of the questionnaire was based on 37 informal interviews with subjects experienced in handling search dogs. The questionnaire probed whether the characteristics would vary depending upon the different use for search dogs and it also asked respondents to compare the characteristics of their current search dogs with the characteristics they reported as most desirable in a search dog. The purpose of the comparison was to identify traits that may benefit from additional attention during the selection process. Results of statistical analysis revealed the 10 most important characteristics of specialist search dogs. Comparisons between the ideal characteristics and actual characteristics indicated significant differences for 22 of the 30 characteristics under examination. Differences were primarily noted for undesirable attributes, suggesting that there is considerable room for improvement in the operational effectiveness of selecting specialist search dog candidates. Tables, references