Abstract Background Due to a large amount of jeopardized myocardium, patients with significant left main coronary artery (LMCA) stenosis have an increased risk of death. For years coronary artery bypass grafting has been considered as the treatment of choice. Recent years brought evidence that led to the reconsideration of percutaneous coronary intervention (PCI) as a valuable alternative. Purpose The purpose of this study was to assess temporal trends in clinical practice and analyse the very long-term outcomes of LMCA PCI in a large tertiary hospital in Poland. Methods Group of 998 individuals undergoing LMCA PCI was selected from medical records of 44,989 patients hospitalized in years 2008-2021. Data on mortality were obtained from the Centre for Information Technology. Temporal trends were calculated for period 2008-2014 as compared to 2015-2021. The 10-year event rate was calculated with the Kaplan-Meier estimator, univariate (ULR), and multivariate logistic regression (MLR). Results The rate of LMCA PCI increased from 2.21% in 2008 to 6.88% in 2021 (p<0.001). 736 (73.8%) patients were male, the median age was 71 years (interquartile range 16). 409 (41.0%) of patients presented with acute coronary syndrome (ACS), 545 (54.6%) with chronic coronary syndrome (CCS). In the analysed periods concomitant diabetes mellitus (DM) rate increased from 27.44% to 42.5% (p<0.001), use of intravascular imaging (IVI) increased from 22.28% to 42.72% (p<0.001), use of rotational atherectomy increased from 8.36% to 18.94% (p<0.001). The 30-day mortality decreased from 10.31% to 4.23% (p<0.001), and 1-year mortality decreased from 18.66% to 12.05% (p=0.007). In the 10-year follow-up 399 (40.0%) patients died. In ULR, death was associated with femoral access (OR 1.766, 95% CI 1.308-2.386) and absorbed radiation dose (OR for increase in 1 Gy 1.192, 95% CI 1.080-1.304). The provisional stenting yielded better performance than two-stent techniques (OR 0.635, 95% CI 0.491-0.821). In MLR, death at 10 years was associated with age (OR 1.028, 95% CI 1.007-1.050), ACS (OR 1.725, 95% CI 1.134-2.624), atrial fibrillation (OR 1.540, 95% CI 1.002-2.367), lower glomerular filtration rate (OR for decrease in 1 ml/min/1.73 m2 1.011, 95% CI 1.001-1.022), and lower left ventricular ejection fraction (OR for decrease in 1% 1.045, 95% CI 1.029-1.060). Better outcomes were associated with previous revascularization (OR 0.668, 95% CI 0.453-0.986), use of IVI (OR 0.518, 95% CI 0.353-0.759), drug-eluting stents (OR 0.238, 95% CI 0.106-0.536) and bigger balloon diameter used for stent optimization (OR for increase in 1 mm 0.889, 95% CI 0.801-0.986). Conclusions In the analysed period the rate of LMCA PCI, number of complex procedures, and co-morbidities increased, yet the prognosis has improved. The 10-year death rate analysis revealed that advancements in percutaneous device technology and procedural techniques are associated with more favourable outcomes.