As coronary interventional technology improves, the influence of lesion length (LL) on procedural success and device selection may vary. Thus, the authors prospectively analyzed 957 consecutive coronary interventions (CI) in 1,404 stenoses to ascertain the influence of lesion length on CI outcome. Stenosis morphology was prospectively classified by the AHA/ACC criteria. LL was analyzed both as dichotomous (S: < 10 mm, L: > 10 mm) variables and by the three-tiered AHA/ACC criteria (I: < 10 mm, II: 10-20 mm, III: > 20 mm). There was a significant univariate relationship between CI success and S stenosis (S: 95.8% vs L: 91.8%, p = 0.002 and I: 96.0%, II: 91.7%, III: 89.3%). Numerous interrelationships involving the morphologic characteristics were noted: lesion morphologies associated with S lesions were concentric (p = 0.0001) and had smooth contour (p = 0.0001), ostial location (p = 0.05) and little calcification (p = 0.0007), while irregular contour (p=0.0001), calcification (p=0.0076), eccentric (p=0.0001), thrombus (p = 0.0001), recent (p = 0.0001) or chronic (p = 0.001) total occlusion were associated with L lesions. When these relationships were taken into account by multiple logistic regression analysis, lesion length was not predictive of procedural outcome (p = 0.099). One morphologic type was associated with increased CI success: irregular contour (p = 0.022); recent (p < 0.0001) or chronic (< 0.0001) occlusions were associated with decreased CI success. Another factor considered was device selection: S lesions were associated with greater balloon angioplasty usage (p = 0.002), whereas more coronary stents (p = 0.024) and rotoblator (p = 0.018) devices were used in L lesions. More balloon angioplasty was performed in concentric (p < 0.0001) lesions; interventional devices were employed more often in eccentric (p < 0.0001) and irregular lesions (p < 0.0001). More complications were noted in lesions with thrombus (p = 0.0002), but lesion length was not predictive (p = NS). Lesion length is not a significant predictor of procedural success when adjusted for other lesion morphologies in the modern interventional era. The availability of new devices has improved the results in longer lesions since the AHA/ACC criteria were originally proposed.