  Primordial Black Holes (PBHs), which may have been created in the early
Universe, are predicted to be detectable by their Hawking radiation. The Fermi
Gamma-ray Space Telescope observatory offers increased sensitivity to the
gamma-ray bursts produced by PBHs with an initial mass of $\sim 5\times
10^{14}$ g expiring today. PBHs are candidate progenitors of unidentified
Gamma-Ray Bursts (GRBs) that lack X-ray afterglow. We propose spectral lag,
which is the temporal delay between the high and low energy pulses, as an
efficient method to identify PBH evaporation events with the Fermi Large Area
Telescope (LAT).
