Geiger counter x‐ray diffractometer patterns of samples with moderate to high radioactivity give a high background, which reduces the precision of the x‐ray‐line intensity and profile measurements. The large amount of lead shielding required to reduce the background is not practical in modern precision goniometers and could not bring as great a reduction as can be achieved with scintillation or proportional counters using pulse‐height discrimination and no shielding. This paper describes a technique using a scintillation counter which permits the measurement of x‐ray patterns from strongly radioactive specimens. A scintillation counter with 0.56 in.×0.16 in.×0.017 in. thick NaI·Tl crystal, 0.005 in. Be window and DuMont 6291 photomultiplier is described, which reduced the background of an 84 mr/hr/10 cm Co60sample from 785 c/sec, measured with a Geiger counter, to 26 c/sec and increased the sensitivity to CuK&agr; by a factor of about 2.5 to 3.