ABSTRACT Background Patients with cancer undergoing cardiac implantable electronic device (CIED) implantation face unique challenges. This study evaluates the outcomes and implications of CIED implantation in this population. Methods Using data from the National Readmission Database (NRD) from 2016 to 2019, we analyzed CIED implantations in patients aged ≥18 years, categorized by cancer status: no cancer, historical cancer, and active cancer. Multivariable logistic and linear regression models assessed associations with in‐hospital, 30‐day, and 90‐day outcomes, adjusting for various patient characteristics. Results A total of 748,957 CIED procedures were analyzed among which 13.3% were in patients with historical cancer and 3.8% with active cancer. Active cancer was linked to higher odds of pacemaker implantation but lower odds for ICD and CRT devices. Patients with active cancer experienced higher index hospitalization mortality (aOR 1.68; 1.50–1.89; p < 0.001), major adverse cardiovascular events (aOR 1.07; 1.02–1.14; p = 0.01), bleeding (aOR 1.36; 1.27–1.46; p < 0.01), and sepsis‐related (aOR 1.31; 1.19–1.44; p < 0.01) complications, with increased readmission rates at 30 (aOR 1.37; 1.30–1.44; p < 0.01) and 90 days (aOR 1.37; 1.31–1.44; p < 0.01) compared to those without cancer. Historical cancer was associated with better outcomes. Key predictors of adverse outcomes included chronic heart failure, kidney disease, cerebrovascular disease, and protein‐calorie malnutrition. Conclusions Patients with active cancer undergoing CIED implantation have an increased risk of in‐hospital complications and readmissions as compared to those without cancer.