BACKGROUND: Lung cancer is one of the most common cancers and poses a physical and psychological threat to patients. Mindfulness-based interventions are emerging forms of psychotherapy that are effective in improving physical and psychological symptoms, but no review has summarized their effectiveness on anxiety, depression, and fatigue in people with lung cancer. OBJECTIVES: To evaluate the effectiveness of mindfulness-based interventions in reducing anxiety, depression, and fatigue in people with lung cancer. DESIGN: Systematic review and meta-analysis. METHODS: We searched the PubMed, Web of Science, Embase, China Biology Medicine disc, Wanfang Data, China National Knowledge Infrastructure, and China Science and Technology Journal databases from inception to 13 April 2022. Eligible studies included randomized controlled trials of people with lung cancer receiving mindfulness-based interventions reporting on the outcomes of anxiety, depression, and fatigue. Two researchers independently reviewed the abstracts and full texts, extracted the data and assessed the risk of bias independently by using the Cochrane 'Risk of bias assessment tool'. The meta-analysis was performed by using Review Manager 5.4, and the effect size was calculated by the standardized mean difference and its 95% confidence interval. RESULTS: The systematic review included 25 studies (2420 participants), whereas the meta-analysis included 18 studies (1731 participants). Mindfulness-based interventions significantly decreased levels of anxiety [standardized mean difference = -1.15, 95% confidence interval (-1.36, -0.94), Z = 10.75, P < 0.001], depression [standardized mean difference = -1.04, 95% confidence interval (-1.60, -0.48), Z = 3.66, P < 0.001], and fatigue [standardized mean difference = -1.29, 95% confidence interval (-1.66, -0.91), Z = 6.79, P < 0.001]. The subgroup analysis indicated that programs lasting less than eight weeks in length with structured intervention components (e.g., mindfulness-based stress reduction and mindfulness-based cognitive therapy) and 45 min of daily home practice implemented in patients with advanced stage lung cancer showed better effects than programs lasting more than eight weeks in length with less structured components and more than 45 min of daily home practice implemented in patients with mixed stage lung cancer. The overall quality of the evidence was low due to the lack of allocation concealment and blinding and the high risk of bias in most studies (80%). CONCLUSIONS: Mindfulness-based interventions might be effective in reducing anxiety, depression, and fatigue in people with lung cancer. However, we cannot draw definitive conclusions because the overall quality of the evidence was low. More rigorous studies are needed to confirm the effectiveness and examine which intervention components may be most effective for improved outcomes.