Statistical Process Control (SPC) methods have become extremely popular in quality control and process improvement in the manufacturing environment, first in Japan and more recently in the U.S. They are gradually being introduced into the research and development setting as well, where they offer some advantages over more traditional statistical approaches. The greatest advantage of the SPC approach is that it ensures that the statistical description generated is valid, i.e., that the data on which it is based incorporate only random error. This is verified both initially and on a continuing basis. This means that the results provide valid predictions of future performance, not just a description of an historical set of replicate samples. SPC statistical evaluations of analytical results and instrument performance require only simple calculations and are easily applied in a consistent, valid manner by statistically unsophisticated analysts. Besides the numerical statistical analysis tools, the SPC approach provides other problem-solving techniques for improvement of the entire analysis process. These aspects of the SPC approach will be described and illustrated with examples from our x-ray fluorescence analysis laboratory.