We report the results of de Haas van Alphen measurements in high magnetic fields on the anisotropic compound LaSb2. Our measurements reveal three extremal orbits of the Fermi surface. One is very small and ellipsoidal, while the remaining two are larger and have a nearly cylindrical shape indicating a quasi-two-dimensional Fermi surface. We compare these measurements with the results of energy band calculations and find reasonable agreement with the measured Fermi surface areas, though the calculations show other multiconnected regions of the Fermi surface not observed in the de Haas van Alphen spectra. The implications of our calculated and measured Fermi surfaces on the mechanisms proposed for the extraordinary large linear magnetoresistance in LaSb2 are discussed.