Background: Cancer presents a progressively deteriorating illness that not only causes significant physical, social and economic burdens in patients but also impacts an individual's psychological well-being and quality of life. Dignity therapy is a well-accepted psychosocial intervention but the effectiveness on hope, quality of life, anxiety, and depression in cancer patients remains inconsistent. Objective: The purpose of this meta-analysis was to identify the effectiveness of dignity therapy on hope, quality of life, anxiety, and depression in cancer patients. Design: A meta-analysis of randomized controlled trials was performed. Methods: Relevant studies published from inception to February 2022 were retrieved from PubMed, Embase (Ovid), the Cochrane Central Register of Controlled Trials, Web of Science, PsycINFO, CINAHL, CBM, CNKI, VIP and Wanfang. The literature search and data extraction processes were conducted by two independent authors. The methodological quality of the included studies was assessed by the Cochrane Risk-of-Bias Assessment Tool, version 2 and the GRADE approach. The data analysis was performed using Review Manager (Version 5.4). Results: Fourteen randomized controlled trials published between 2011 and 2021 were included. Most of the studies were assessed as having some concerns. The certainty of the evidence in this review varied from low to high across outcomes. The meta-analysis showed statistically significant effects of dignity therapy on hope (mean difference (MD) = 3.41, 95% CI: 2.82 to 4.00, P < 0.001), anxiety (standardized mean difference (SMD) = -0.75, 95% confidence interval (CI): -1.32 to -0.18, P = 0.01), and depression (SMD = -1.01, 95% CI: -1.60 to -0.43, P = 0.0007) at postintervention, and the separate analysis revealed that dignity therapy had a sustainable effect on anxiety (MD = -2.96, 95% CI: -3.85 to -2.07, P < 0.001) and depression (MD = -3.44, 95% CI: -6.20 to -0.68, P = 0.0003) at one month after the intervention. However, no statistically significant effect on quality of life were found in our study. Conclusion: Dignity therapy may be effective for improving hope, anxiety, and depression among adult cancer patients, but the effect on quality of life is nonsignificant. Culture-tailored dignity therapy should be further focused and explored. More randomized controlled trials with larger sample sizes, multiple follow-up times, and strict study designs should be further conducted to identify the effect of dignity therapy on cancer patients. (C) 2022 Elsevier Ltd. All rights reserved.