The microstructure of the superalloy CM186LC exhibits a pronounced dendritic character. The microstructure within the dendrite arms consists of cuboid gamma' precipitates, separated by narrow channels of gamma matrix that contains nano-sized, spherical secondary gamma' precipitates. Between the dendrite arms, gamma/gamma' eutectic areas and carbide particles could be observed. Quantitative microstructural investigations of the alloy were performed by means of transmission electron microscopy methods. The microstructural parameters, influencing the mechanical properties of the alloy (mean size of gamma' particles, mean particle spacing, shape coefficients of cuboidal gamma' precipitates and relative projection area), were determined. (C) 2003 Elsevier Science B.V. All rights reserved.