The in situ soil gamma analyzer is an instrument constructed to measure the position of gamma-emitting trace elements in soil. It consists of a solid state scintillator, a lead shield with a 3-mm-wide horizontal window, and a portable analyzer. When the detector is lowered into a circular excavation dug vertically into the soil of interest, the gamma activity of the tracer is plotted as a function of depth thus yielding a profile of the tracer distribution. Because of a broad base profile in the original plotted data, which is due to soil attenuation and the lack of collimation, a computer program was written to replot the distribution pattern to within ± 1 mm of actual position. By making a series of time-related measurements, the rate of pollutant movement in soil is obtained.