•ADF-STEM is powerful technique for 3D location of substitutionally doped atoms.•The effects of specimen mistilt on ADF-STEM imaging of doped atoms are evaluated.•Visibility changes over 0–30 mrad mistilts are large enough to preclude 3D dopant location.•Dopant visibility is a strong function of specimen mistilt and cannot be ignored. Quantitative ADF-STEM imaging paired with image simulations has proven to be a powerful technique for determining the three dimensional location of substitutionally doped atoms in thin films. Expansion of this technique to lightly-doped nanocrystals requires an understanding of the influence of specimen mistilt on dopant visibility due to the difficulty of accurate orientation determination in such systems as well as crystal movement under the beam. In this study, the effects of specimen mistilt on ADF-STEM imaging are evaluated using germanium-doped silicon nanocrystals as model systems. It is shown that dopant visibility is a strong function of specimen mistilt, and the accuracy of specimen orientation is an important factor in the analysis of three-dimensional dopant location, but the sensitivity to mistilt can be weakened by increasing the STEM probe convergence angle and optimizing ADF detector inner angle. Display omitted