An examination of the secondary sex characteristics of 3197 adult specimens of Sorex (Soricomorpha, Soricidae), including 50 species, processed by 560 preparators over 126 y, and housed in 18 mammal collections, revealed that the sex of 9.57% of these specimens was misidentified or not identified. If only the 20 species for which I examined ≥20 specimens are considered, the sex of 5.82% of males and 15.89% of females was misidentified or not identified. Diverse methods of determining sex are available, although their use necessarily depends on the age of animals and whether they are dead or alive. For live shrews, examination of the secondary sex characteristics, distance between the urogenital and excretory openings, and presence or absence of sex chromatin can be used to identify the sex. For dead shrews, sex also can be determined by dissection of reproductive systems, examination of pelvic bones and determination of karyotypes. Of genetic methods, the Sry gene is the best characterized for identification of the sex of live or dead shrews. Several techniques are described for determining sex of specimens of shrews, however, due diligence must be observed by application of the appropriate technique(s) within the capabilities of specimen collectors or preparators that will provide the correct results.