To review the evidence for a systematic relationship between cancer patients' pre-treatment expectations (anticipated side effects) and subsequent experience of treatment-related side effects, and to compare this relationship in patients with no prior treatment experience (cognitive expectations) and with some prior treatment experience (conditioned response).A total of 12,952 citations were identified through a comprehensive search of the literature published on or before November 2016 and screened against inclusion criteria. Studies were eligible if they included participants undergoing curative treatment for cancer, measured a treatment side effect, examined the relationship between anticipation and experience of side effects, and reported quantitative data.Thirty-one studies were included in the review and meta-analysis (total N = 5069). The side effects examined were nausea (anticipatory and post-treatment), vomiting, fatigue, pain, problems with concentration, and skin reactions. Meta-analyses indicated positive associations between anticipation and subsequent experience for all included side effects in patients with no prior treatment exposure (r = 0.153-0.431). Stronger associations were found for all included side effects in patients with previous treatment experience (r = 0.211-0.476), except for fatigue (r = 0.266) and pain (r = 0.235). No significant differences were found when overall effect sizes for patients with and without prior treatment exposure were compared for each side effect, except for anticipatory nausea (p = 0.012).These results may have implications for future interventions that target patients' expectations of cancer treatment-related side effects. Future research could explore patient reports of messages received about likely treatment effects both before and during treatment.