Objectives To compare the discriminatory value of differing risk scores for predicting clinical outcomes following PCI in routine practice. Background Various risk scores predict outcomes after PCI. However, these scores consider markedly different factors, from purely anatomical (SYNTAX risk score [SRS]) to purely clinical (ACEF, modified ACEF [ACEFmod], NCDR), while other scores combine both elements (Clinical SYNTAX score [CSS], NY State Risk Score [NYSRS]). Methods Patients with triple vessel and/or LM disease with 12 month follow-up were studied from a single center PCI registry. Exclusion criteria included STEMI presentation, prior revascularization and shock. Clinical events at 12 months were compared to baseline risk scores, according to score tertiles and area under receiver-operating-characteristic curves (AUC). Results We identified 584 eligible patients (69.8±12.3yrs, 405 males). All scores were predictive of mortality, with the SRS being least predictive (AUC=0.66). The most accurate scores for mortality were the CSS and ACEF (AUC=0.76 for both: P = 0.019 and 0.08 vs. SRS, respectively). For TLR, while the SRS trended toward being positively predictive (P = 0.075), several scores trended towards a negative association, which reached significance for the NCDR (P = 0.045). The SRS and CSS were the only scores predictive of MI (both P < 0.05). No score was particularly accurate for predicting MACE (death+MI+TLR), with AUCs ranging from 0.53 (NCDR) to 0.63 (SRS). Conclusions Competing factors influence mortality, MI and TLR after PCI. An increasing burden of comorbidities is associated with mortality, whereas anatomical complexity predicts MI. By combining these outcomes to predict MACE, all scores show reduced utility.