Luffaculin 1 purified from the seeds of Luffa acutangula belongs to the type 1 ribosome-inactivating proteins (RIPs). It has been crystallized by the vapor-diffusion method using polyethylene glycol as a precipitant. The crystal is of space group P1 with a = 39.135, b = 46.813,c= 83.571 (A), α = 89.068, β = 80.009 and γ = 72.143°, and has two molecules per asymmetric unit.X-ray data have been collected to be 1.4 (A) using a synchrotron source.