Nanoscale CrN/NbN multilayer PVD coatings have exhibited resistance to erosion–corrosion. However growth defects (under dense structures and droplets) in the coating produced by some deposition technologies reduce the ability to offer combined erosion–corrosion resistance. In this work a novel High Power Impulse Magnetron Sputtering (HIPIMS) technique has been utilised to pretreat substrates and deposit dense nanoscale CrN/NbN PVD coatings (HIPIMS–HIPIMS technique). This new technique, rich with metal ion plasma, deposits very dense structures and offers virtually defect free coatings (free of droplets as observed in cathodic arc technique and under-dense structures observed in standard dc sputtering). Plasma diagnostic studies revealed a high metal ion-to-gas ion ratio (Cr:Ar) of 3:1 for HIPIMS pretreatment conditions with the detection of 14% Cr 2+ and 1% Cr 3+ ions and J s of 155mAcm −2 . For deposition conditions the metal ion-to-gas ratio was approximately 1:4 which is significantly higher compared to DC at 1:30. Characterisation results revealed a high adhesion of L C 80N, high hardness of 34GPa and Young's modulus of 381GPa. Low friction coefficient (0.46) and dry sliding wear coefficient, K C (1.22×10 −15 m 3 Nm −1 ) were recorded. The effect of deposition technique (droplet defect and intergranular void free coatings) on erosion–corrosion resistance of CrN/NbN coatings has been evaluated by subjecting the coatings to a slurry impingement (Na 2 CO 3 +NaHCO 3 buffer solution with Al 2 O 3 particles of size 500–700µm) at 90° impact angle with a velocity of 4ms −1 . Experiments have been carried at −1000mV, +300mV and +700mV representing 3 different corrosion conditions.