Previous investigations have revealed that Atomic Layer Deposition (ALD) layers on Physical Vapor Deposition (PVD) coatings lead to pinhole defect sealing, which results in improved coating corrosion properties. However, despite this, the influence of PVD defect size on the sealing efficiency of ALD layers remains poorly determined. This study aimed to evaluate the corrosion properties of hybrid PVD/ALD layers with a focus on how the influence of PVD defect size affects the sealing efficiency of ALD layers. The corrosion resistance of PVD TiN coatings and TiN combined with ALD Ti-O layers (amorphous and anatase phases) was investigated in phosphate-buffered saline solution (PBS). Corrosion experiments were conducted on circular areas of 4 mm in diameter using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PD) measurements. Confocal and tactile profilometry were performed before and after the corrosion tests to identify and quantify the PVD coating growth defects. To examine the thickness and uniformity of the ALD layers, scanning electron microscopy (SEM) was utilized on cross-sections of PVD defects prepared by focused-ion beam (FIB). The results revealed that the increased number of protrusion defects, with heights exceeding 2 µm, correlates with a decrease in impedance for PVD-coated samples. The deposition of ALD layers significantly improved the corrosion resistance of samples. Cross-sectional FIB-SEM analysis confirmed uniform coverage by the ALD layer without visible cracks across all investigated ALD layers. However, corrosion tests revealed that the amorphous TiO₂ ALD layer exhibited superior PVD defect-sealing efficiency compared to the anatase TiO₂ layer. This suggests that the presence of grain boundaries in the anatase TiO₂ ALD layer contributes to its lower sealing efficiency. The application of ALD layers on PVD-coated samples, by forming a hybrid coating, offers a promising solution for applications requiring enhanced corrosion resistance alongside adequate surface mechanical properties.