Dimensional metrology for micro- and even nanometer-sized objects is becoming increasingly important in industry branches like semiconductor and optical industries as well as in the fields of mechanical engineering, biology and medicine. To achieve the required small uncertainties and probing flexibility new measurement systems have been developed in the recent years. This paper introduces some dimensional metrology research activities at the Physikalisch-Technische Bundesanstalt (PTB). A metrological large range AFM with a capable measurement volume of 25 × 25 × 5 mm3 is introduced for versatile measurements of micro-/nanostructures. A special assembled cantilever probe (ACP) which is applicable for direct and non-destructive sidewall measurements is presented. Furthermore, a true 3D AFM using flared AFM probes is described. Finally, the challenges in form metrology are discussed and an ultra precision CMM applicable for form measurements are introduced.