We search for the decays B-→ K-γ and B̄0→ K̄0γ in a data sample of 228×106 BB̄ pairs collected at the Υ(4S) resonance with the BABAR detector. We measure the branching fraction B(B-→ K-γ)=(3.5±0.6±0.4)×10-6 and set an upper limit B(B̄0→ K̄0γ)<2.7×10-6 at the 90% confidence level. We also measure the direct CP asymmetry in B-→ K-γ, ACP=(-26±14±5)%. The uncertainties are statistical and systematic, respectively. © 2007 The American Physical Society.