During 1993 and 1994 an extensive qualitative survey was conducted on the unionid community in Patterson Creek, an Atlantic slope stream in Grant and Mineral counties, West Virginia. The primary purpose of this survey was to determine the status of two federal species of concern. Unionids were found at 17 of the 23 sites surveyed and represented eight species. The number of taxa per site ranged from 0 to 6. The taxon listed as Lampsilis spp. may represent either the native L. cariosa, the introduced L. cardium, or both with possible intergrades. Lampsilis spp. were observed alive at 11 sites, and empty shells were found at an additional six sites. Alasmidonta varicosa (federal species of concern) was found alive at 12 of the 23 sites and shell material at an additional two sites. Specimens of A. varicosa ranged from 25.1 mm to 80.2 mm in length, and appeared to represent a healthy reproducing population. Only one valve of Lasmigona subviridis (federal species of concern) was observed in Patterson Creek during this survey. Other species found during this survey included Alasmidonta undulata, Elliptio complanata, E. fisheriana, and Strophitus undulatus. Although many impacts were evident throughout the watershed (i.e., cattle access to the stream, streambank degradation, lack of riparian canopy, storm-water runoff, poultry farming, and increased urbanization) this stream has a relatively diverse unionid fauna. Knowing what still remains in Patterson Creek today, we can only speculate, due to the lack of historical data, that this stream must have once been home to a diverse and abundant unionid fauna.