Five hundred seventy-two Sceloporus occidentalis from Los Angeles County, California, were examined for helminths: 200 from the San Gabriel Mountains (montane, ca. 1584 m elevation) and 372 from the Puente Hills (lowland, ca. 150 m elevation). The component helminth community of the montane fence lizard population consisted of four species: two species of cestodes, Mesocestoides sp. and Oochoristica scelopori and two species of nematodes, Physaloptera retusa and Spauligodon giganticus. The component helminth community of the lowland fence lizard population contained three species: Mesocestoides sp., Physaloptera retusa and unidentified nematode acuariid larvae. The two helminth communities are dissimilar in composition.