Parasitoid flies of white cedar sawfly, Monoctenus sanchezi Smith, were identified molecularly and morphologically. Third and fourth instars of sawfly larvae were collected in white cedar trees, Juniperus flaccida Schltdl, at Sierra de Alvarez, San Luis Potosi, in 2011, 2012, and 2013. The material collected was taken to Universidad Autonoma Agraria Antonio Narro and identified to family. Molecular characterization was done at CINVESTAV Campus Irapuato, and DNA sequences were compared with GenBank Blast. Parasitoids obtained were Vibrissina mexicana (Aldrich) and Lespesia postica (Walker) (Diptera: Tachinidae) with 99 and 97% similarity, respectively. Parasitism of white cedar sawfly was 2.6, 4.25, and 5.5% in 2011, 2012, and 2013, respectively.