Population screening studies have identified that up to two thirds of celiac disease (CD) cases are asymptomatic. The aim of this study was to conduct a systematic review of the expected consequences of testing for CD in the following populations: (1) patients with symptoms suggestive of CD, (2) asymptomatic at-risk populations, and (3) general population. Standard systematic review methodology was used. A comprehensive literature search was conducted in MEDLINE (1996-2003), EMBASE (1974-2003), CAB (1972 forward), PsychINFO (1840-2003), AGRICOLA (1970-2003), and Sociological Abstracts (1963 forward); searches were conducted in December 2003. Pooled summary estimates were not calculated. The majority of the included studies were before-after studies, case control, or retrospective cohorts. The quality of evidence for the before-after studies is weaker. The overall strength of the evidence for this issue was fair to good. This area of research is relatively new, and further high-quality studies are required. The consequences of testing for celiac disease in symptomatic individuals appears to have a positive impact on patient-relevant outcomes. The data are less clear for those with silent CD or those with lower grade histologic lesions in small bowel biopsy. The literature suggests that compliance is less than ideal in these individuals, especially if diagnosed when adults. Long-term outcomes have not been extensively studied in those with silent CD.