OBJECTIVES: Assessment of the appropriateness of screening programs involves consideration of the harms as well as the benefits. These harms include the risk of false-negative results, the consequences of which have remained underinvestigated. This paper reports the results of a systematic literature review that aimed to assess the medical psychological, economic, and legal consequences of false-negative results in national screening programs. METHODS: The review included a comprehensive literature search and contact with experts to identify relevant literature. Most studies that were identified presented only anecdotal evidence. However, thirteen studies presented quantitative information on medical consequences of false negatives, eight studies presented information on psychological consequences, and two studies presented information on economic consequences. RESULTS: The strength of evidence from most of the primary studies was low. There is some evidence, however, that false-negative results may have a large legal impact. There is also a consensus in the literature that false negatives may have a negative impact on public confidence on screening; evidence is however limited. CONCLUSIONS: False negatives are evident even in high-quality screening programs. They may have the potential to delay the detection of breast and cervical cancer, but there is little evidence to help in assessing their psychological consequences. They also may lead to legal action being taken by those affected and may reduce public confidence in screening. Their impact may be reduced by provision of full information to participants about the benefits and limitations of screening programs and by increasing public education on these issues.