Background The double kissing (DK) crush technique is a modified version of the crush technique.It is specifically designed to increase the success rate of the final kissing balloon post-dilatation,but its efficacy and safety remain unclear.Methods Data were obtained from the DKCRUSH-I trial,a prospective,randomized,multi-center study to evaluate safety and efficacy.Post-procedural and eight-month follow-up intravascular ultrasound (IVUS) analysis was available in 61 cases.Volumetric analysis using Simpson's method within the Taxus stent,and cross-sectional analysis at the five sites of the main vessel (MV) and three sites of the side branch (SB) were performed.Impact of the bifurcation angle on stent expansion at the carina was also evaluated.Results Stent expansion in the SB ostium was significantly less in the classical crush group ((53.81±13.51)％) than in the DK crush group ((72.27±11.46)％) (P=-0.04).For the MV,the incidence of incomplete crush was 41.9％ in the DK group and 70.0％ in the classical group (P=-0.03).The percentage of neointimal area at the ostium had a tendency to be smaller in the DK group compared with the classical group ((16.4±19.2)％ vs.(22.8±27.1)％,P=-0.06).The optimal threshold of post-procedural minimum stent area (MSA) to predict follow-up minimum lumen area (MLA) ＜4.0 mm2 at the SB ostium was 4.55 mm2,yielding an area under the curve of 0.80 (95％ confidence interval:0.61 to 0.92).Conclusion Our data suggest that the DK crush technique is associated with improved quality of the final kissing balloon inflation (FKBI) and had smaller optimal cutoff value of post-procedural MSA at the SB ostium.