Bronchial artery embolization (BAE) is almost the only effective nonsurgical treatment for massive hemoptysis. Metallic coils with plastic fibers are widely used as embolic materials. We have introduced an interlocking detachable coil (IDC) for BAE. IDC is a mechanically detachable coil, allowing the operator to seek the ideal shape until its final release. We compared hemoptysis patients treated with conventional metallic coils (24 patients, non-IDC group) with those treated with conventional coils and IDCs (26 patients, IDC group). The hemoptysis rate after three months is significantly lower in the IDC group than in the non-IDC group (7.7% vs. 16.3%, p=0.035 Fisher's exact method). Total procedure time (in staged or repetitive BAE cases, procedure times are added together) is significantly shorter in the IDC group than in the non-IDC group (3.4± 1.4 hours vs. 4.4± 2.5 hours, p=0.040 unpaired t-test). IDC is a useful device for BAE. This is the first-ever report documenting the usefulness of IDC for BAE.