Seventy-five intact Mimbres and Jornada pottery sherds from the American Southwest were analyzed by portable XRF and instrumental neutron activation analysis (INAA). Examination of the data demonstrates that INAA and portable XRF results for elements common to both analyses can be used to construct similar compositional groups. When individual compositional groups are compared to one another, it is apparent that unambiguous separation of compositional groups is challenging by portable XRF given (1) the limited number of key discriminating elements that can be measured relative to INAA, and (2) the relative analytical precision and accuracy of portable XRF for measurements of intact heterogeneous ceramics. We conclude that sourcing intact ceramics by portable XRF is challenging and that bulk analytical measurements, such as INAA, remain a better approach for sourcing archaeological pottery.