The majority of dioecious plants are not sexually dimorphic until the onset of reproductive maturation. The inability to identify sex in pre-reproductive plants limits sex-related studies in plant populations. Molecular techniques to identify sex in seed plants have had increasing success. However, sex-specific markers in bryophytes have not yet been found. Bryophytes can be effective model systems in understanding the reproductive biology of plant species with unisexual individuals, as well as the molecular biology of sex chromosomes and sex determination. This study was specifically designed to find sex-specific markers in Sphaerocarpos texanus. The study relied on the Polymerase Chain Reaction procedure to amplify arbitrary regions of genomic DNA to locate sex-specific markers. Bulk segregant analysis using 238 decamer primers, and involving a single full-sibling pedigree was used to identify sex-specific markers. Inheritance of specific markers by male or female individuals was tested in progeny derived from two mated pairs involving individuals in the pedigree. Consistency of the markers was tested with individuals outside the original pedigree in the same population as well as with individuals from a distant population. Four markers were found—three specific to females and one specific to males.