We report the results of a 2-yr survey aimed at determining the identity and abundance of native parasitoids of fruit infesting tephritids attacking Psidium guajava L. (common guava) in the endangered northernmost Yungas forests of Argentina, which are being encroached by commercial citrus groves. The 3,200 guavas collected during the peak of the short guava fruiting period (February and March), yielded 10,701 Anastrepha fraterculus (Wiedemann) and Ceratitis capitata (Wiedemann) adults (97.4 and 2.6%, respectively) and 712 native parasitoids. The parasitoid species and proportion in the total sample during the 2-yr study period were as follows: Doryctobracon areolatus (Szépligeti), 37.9%; Doryctobracon brasiliensis (Szépligeti), 17.7%; Utetes anastrephae (Viereck), 1.1%; Opius bellus (Gahan), 0.7%; (all Braconidae, Opiinae), and Aganaspis pelleranoi (Brèthes), 32.6% (Figitidae, Eucoilinae). All parasitoids emerged from A. fraterculus pupae (i.e., none from C. capitata). The discovery of D. crawfordi represents the first report for Argentina and the southernmost record for the species. We discuss the practical implications of the role of guava as a reservoir for A. fraterculus and the implications for the biological control of both fruit flies. We also update the taxonomic status of the opiine parasitoids of A. fraterculus in Argentina given that a number of species previously reported in the literature had never been formally described (i.e., represent nomina nuda) or had been misidentified.