Aims: To investigate whether the use of intravascular ultrasound virtual histology (IVUS-VH) leads to any improvements in stent deployment, when performed in patients considered to have had an optimal percutaneous coronary intervention (PCI) by quantitative coronary angiography (QCA). Methods and results: After optimal PCI result (residual stenosis by QCA <30%), IVUS-VH was performed in 100 patients by protocol, with the option to use the information left to the discretion of the operators. Patients were categorised as: Group1 (n=54), where the IVUS-VH findings were used to evaluate the need for further optimisation of the stent deployment; and Group2 (n=46), where the IVUS-VH was documentary such that the stenting results were considered optimal according to QCA. Optimal stent deployment on IVUS-VH was defined as: normal stent expansion, absence of stent malapposition, complete lesion coverage as indicated by a plaque burden (PB%) between 30-40% and necrotic core confluent to the lumen <10% or PB%<30% at the 5 mm proximal and distal to the stent. The first IVUS-VH in all patients demonstrated the achievement of optimal stent deployment, incomplete lesion coverage, stent under-expansion and stent-edge dissection in 60%, 31%, 20% and 8% of patients, respectively. There was no stent malapposition. In Group 1, 25 patients had optimal stent deployment and did not require further intervention, whilst in 29 patients further intervention was needed (additional stent, n= 18; post-dilatation, n=29). Overall optimal stent deployment was finally achieved in 52/54 patients (96%) in Group 1 and 35/46 (76%) of Group 2, p<0.05. Conclusions: IVUS-VH may have a role in facilitating optimal stent implantation and complete lesion coverage.