The presence of columnar electron‐ion recombination luminescence from &agr; particles and fission fragments in an argon gas scintillation counter having a few percent N2as waveshifter has been established. A decrease in luminescence yield with applied electric field indicates a loss of recombination luminescence by ion collection. For a U235fission counter at two atmospheres pressure, a reduction in mean scintillation pulse height of 40% for fission fragments and 3% for background U234alphas resulted at 1200 v/cm. It is concluded that columnar electron‐ion recombination luminescence accounts for the considerable nonlinearity of energy response previously reported in gas scintillation counters for heavily ionizing particles.