Background Preparedness for caregiving could balance the negative impacts of caregiving. The interventions aimed at increasing readiness among the caregivers are important during the illness period for both patients and their caregivers. Objectives The aims of this study were to review the interventions applied to the caregivers of cancer patients and to examine the effects of these interventions on the preparedness to care. Methods The ScienceDirect, Scopus, CENTRAL, Web of Science, MEDLINE, and PubMed were searched for relevant studies published between 2000 and 2020. The methodological quality was assessed using the Quality Assessment Tool for Quantitative Studies. The statistical analyses were performed using the Comprehensive Meta-Analysis software version 3.0. The publication bias was assessed using the Egger test, for funnel plots. Results Eleven studies were selected for the meta-analysis, including those about psychoeducation programs (n = 5), education programs (n = 3), supportive programs (n = 2), and a self-care support program for the caregivers (n = 1). The methodological quality assessment revealed 2 studies as "strong." The results indicated an increase in the caregivers' preparedness to care after the interventions. The subgroup analysis revealed that the programs with higher ratios of female caregivers were more effective. Conclusion The interventions applied to the family caregivers can exert beneficial effects on caregivers' preparedness to care. Nonetheless, future studies should focus on methodological issues, such as randomization and blinding. Implications for Practice Nurse-driven interventions may be used as a useful strategy to improve the preparedness to care among the caregivers of cancer patients. The male caregivers should be closely followed by healthcare professionals for knowledge and support needs.