Fast pulsations, characterized by half‐widths of 2–10 seconds and temporal spacings of 4–30 seconds, in the intensity of auroral‐zone X rays have been investigated using simultaneous pairs of balloon‐borne detectors with spatial separations of approximately 100–200 km. Such events, usually of an hour's duration, occur almost exclusively in the midnight to dawn sector (0200–0800 local hours) and appear preferentially on the equatorward side of the auroral zone. Spectral analysis shows the phenomena to be nonstationary but suggests that quasi‐periods of 5–10 seconds ought to be considered a significant feature of the process responsible for such variations. Cross‐correlation studies confirm the limited spatial extent of individual pulsations, on the average, and further indicate the possibility of longitudinal motions. Microburst events, characterized by scores of transient bursts each of about 200‐msec half‐width, occur most frequently around local noon, favoring the late morning and early afternoon. There appears to be little average latitude dependence across the auroral zone. Individual events, however, may be quite restricted in latitude. On one occasion, microbursts were observed for the better part of 3 hours atL= 5.5 in the absence of similar activity atL= 6.5, suggesting a rather localize