Abstract We describe studies of the light yield of scintillators as a function of an externally applied magnetic field. The studies involved using fluoroscopic measurements, measuring indices of refraction, employing a wide variety of sources from fission fragments to cosmic rays, and making measurements as a function of the scintillator type and thickness and of the direction of the applied field. We observed the light yield to increase with increasing magnetic field, independent of geometry or direction of the magnetic field. The effect was much larger in acrylic scintillator than in polyvinyltoluene or polystyrene-based scintillator. We believe that the change in the light yield is due to a local light saturation of the material. As the magnetic field increases, the low-energy electrons spiral away from each other and the light yield increases.