Low-Lu LGSO scintillators (Lu0.4Gd1.6SiO5: 2.0 mol% Ce) were evaluated with Si PIN photodiode. An LGSO scintillator (2 mm × 2 mm × 4 mm) was coupled to a Si PIN photodiode (HAMAMATSU S1337-33BR). Spectroscopic and timing performance of the LGSO/Si PIN detector was investigated at room temperature. The LGSO/Si PIN detector was irradiated with a 22Na source. The energy resolutions of LGSO/Si PIN detector for the 511 keV full-energy peak was measured to be 17.7% (90.7 keV FWHM). The 511 keV peak position was found to correspond to 3793 e- (conversion factor of 7.4 eVkeV). A coincidence timing spectrum was acquired with the LGSO/Si PIN detector and the reference BaF2 detector. The coincidence timing resolution was measured to be 57 ns FWHM.