A series of intercalated transition-metal dichalcogenides with nominal compositions A x NbCh 2, with A=Cu, Co, Fe, Ch=S, Se and x=0.25, 0.33, were studied by scanning tunneling microscopy (STM). Evidence is given that intercalation influences the STM images. Intercalated Cu atoms occupy tetrahedral interstices in the van der Waals gaps, forming pairs with Nb atoms and adopting the 2H b–MoS 2 stacking of the host structure. Effects associated with non-stoichiometry, such as formation of agglomerates and incomplete ordering of the intercalated Cu are frequently observed. Fe and Co atoms occupy octahedral interstices in the gaps, form chains with alternating Nb and stabilize the 2H a–NbS 2 polytype. In case of (Fe,Co) x NbS 2 2a 0×2a 0 and √3a 0×√3a 0 hexagonal superstructures are formed for x=1/4 and x=1/3, respectively, while in case of Cu x Nb(S,Se) 2 only the x=1/4 fraction orders into a 2a 0×2a 0 hexagonal superstructure at room temperature. In all cases the superstructures are visible at the surfaces and are attributed to changes in the local densities of states caused by a charge transfer between the intercalated and the surface atoms. Typically these superstructures were observed to change during prolonged scanning, probably as a result of tip-induced fluctuations in the charge density. The experimental STM images are compared to simulated images calculated with the extended Hückel tight binding approximation.