['Renal insufficiency (RI) is frequent in patients eligible for cardiac resynchronization therapy (CRT) and may be worsened by the use of contrast agents. We sought to determine the feasibility of CRT implantation without contrast injection in patients with contraindication to iodine.', 'Patients eligible for CRT and presenting with RI were prospectively included (non-contrast NC group). A contemporary control group (CG) of CRT patients with contrast injection was used for comparison. An over-the-wire coronary sinus (CS) lead with an angled distal tip was selected for this "blind harpooning" technique.', 'Seventeen patients in the NC group were included (78 ± 7 years). Serum creatinine was 208 ± 86 μmol/L (glomerular filtration rate 33 ± 15 mL/min/1.73 m(2)). CG included 25 patients (70 ± 7 years, serum creatinine 85 ± 21 μmol/L). CRT implantation was successful in 16/17 patients (94.1 %) without contrast injection. The mean procedure and fluoroscopy times were similar in the two groups: 146 ± 29 in the NC group versus 153 ± 25 min (p = 0.57) and 25 ± 12 in the NC group versus 23 ± 16 min (p = 0.7) respectively. The mean CS lead implantation time was 36 ± 19 (NC group) versus 39 ± 15 min (p = 0.64). No major procedure-related complications were observed in both groups.'] Is non-contrast cardiac resynchronization therapy implantation feasible in case of renal insufficiency?