We demonstrate an atomic force microscopy based method for estimation of defect density by identification of threading dislocations on a non-flat surface resulting from metamorphic growth. The discussed technique can be applied as an everyday evaluation tool for the quality of epitaxial structures and allow for cost reduction, as it lessens the amount of the transmission electron microscopy analysis required at the early stages of projects. Metamorphic structures with low surface defectivities (below 10(6)) were developed successfully with the application of the technique, proving its usefulness in process optimisation. (C) 2015 Elsevier B.V. All rights reserved.