This is the author accepted manuscript. The final version is available at http://onlinelibrary.wiley.com/doi/10.1002/pon.3833/abstract. ; Background: Emotions may be important in patients? decisions to seek medical help for symptoms suggestive of cancer. Objectives: The aim of this systematic literature review was to examine quantitative literature on the influence of emotion on patients? help-seeking for symptoms suggestive of cancer. The objectives were to identify: (1) which types of emotions influence help-seeking behaviour; (2) whether these form a barrier or trigger for seeking medical help; and (3) how the role of emotions varies between different cancers and populations. Methods: We searched four electronic databases and conducted a narrative synthesis. Inclusion criteria were studies that reported primary, quantitative research that examined any emotion specific to symptom appraisal or help-seeking for symptoms suggestive of cancer. Results: Thirty-three papers were included. The studies were heterogeneous in their methods and quality and very few had emotion as the main focus of the research. Studies reported a limited range of emotions, mainly related to fear and worry. The impact of emotions appears mixed, sometimes acting as a barrier to consultation whilst at other times being a trigger or being unrelated to time to presentation (TTP). It is plausible that different emotions play different roles at different times prior to presentation. Conclusions: This systematic review provides some quantitative evidence for the role of emotions in help-seeking behaviour. However, it also highlighted widespread methodological, definition and design issues among the existing literature. The conflicting results around the role of emotions on TTP may be due to the lack of definition of each specific emotion. ; This paper presents independent research funded by the National Institute for Health Research Programme Grants for Applied Research programme (RP-PG-0608-10045). The views expressed are those of the authors and not necessarily those of the National Health Service, the National Institute for Health Research, or the Department of Health. FMW was funded by a NIHR clinical lectureship then an NIHR Clinical Scientist Award.