A paleomagnetic study of Paleocene, Cretaceous, and Jurassic units in the Precordillera of northern Chile (26 ¿S to 27 ¿S) demonstrate a complex pattern of crustal rotations. The region was selected to investigate the pattern of deformation associated with the Sierra Castillo-Agua Amarga Fault and its associated structural subdomains, which form part of the Domeyko Fault System, the fault system that controls much of the structure of the Chilean Precordillera. Paleocene lavas from the center of the study area pass a fold test, indicating the primary nature of the remanence in these rocks. A second group of lavas from the south has a similar formation mean inclination after tilt correction for a uniform dip, which coupled with the presence of reversals, suggests that these lavas also carry a primary remanence. The data indicate clockwise rotations of ~35¿ and 42¿ respectively, for the two sampling localities. Three geographically separate areas of Lower Cretaceous red beds also reveal primary remanences based on the presence of sites with reversed polarity at two of the localities and an inclination-only fold test of the three locality mean directions for this formation. These sampling areas yield remanence directions that reveal 30¿ of counterclockwise and 31¿ of clockwise rotation as well as an area without statistically significant rotation. These data include the first well-constrained counterclockwise rotation to be recovered from rocks in the southern central Andes, although mapping suggests the block involved is of limited geographic extent. Jurassic strata failed to yield any reliable results. Overall, the data indicate a greater variability in the rotation pattern than has previously been observed in most comparable areas south of the Arica Deflection. The variation cannot be explained by large-scale rotation mechanisms, such as oroclinal bending or domino-style block rotation by widely separated transandean faults. Instead, the rotations are consistent spatially, and temporally and in their sense and magnitude with the Eocene transpressional deformation associated with the Domeyko Fault System; the deformational event that generated most of the important structures in the studied area. The data emphasize the significance of local tectonics in controlling rotations in this part of the south central Andes and the importance of understanding the local structure of regions sampled for paleomagnetic study. ¿ 2001 American Geophysical Union