Dimensional control, as one of the important parameters in quality control, needs tools that can extract the required dimensions quickly and accurately. Dimensional control of complex shapes is not something that can be easily and quickly achieved with old methods such as gages or even using electronic sensors. Machine vision techniques and image processing are considered as a new science that provides quality control of the body's exterior features such as size, color, shape, etc. accurately and quickly. In recent years, significant improvements have been made in the field of machine vision and image processing. Measurement of micro parts and/or with a few micron accuracy, is not possible by mechanical methods such as caliper, micrometer etc. Examples of measured parts include watch gears and shape molds for forming wires of diameter of 0.15 and 0.3 mm. The purpose of this research is to design and construct a system for measuring geometric parameters of small gears and a micro-form die using machine vision technology. The developed system operates in a fully automated manner so that after performing preprocessing operations such as noise reduction, improving the contrast and calibration by performing operations such as segmentation, edge detection and mathematical calculations, geometric parameters of the gears and the micro-forming die are obtained. Some MATLAB codes are prepared to obtain desired geometrical features such as: center of the rotation, the number of teeth, diameter of the addendum, the diameter of the dedendum and radius of the groove of the micro-dies, as well as distance of the center of the groove from the edge of the forehead of the die. Among the of the advantages of this method of measurement are: low cost, no need to enter the standard nominal values, speed and accuracy of measurements, no influence of human error in the results of the measurement and simultaneous iection of all the parameters required in one step. Components of measuring system used in this research are; a 5-megapixel digital microscope with a magnification of 20 to 220 X and a red LED light with a wavelength of 690 nm. The light was used below the part, to remove additional shadows and to obtain a high contrast on the workpiece. The digital microscope was calibrated by using a calibration sheet of a video measuring machine. The results of the proposed method were compared with the results of a video measuring machine and the maximum difference was 0.02 mm. Keywords: Machine vision, Image processing, Digital microscope, Micro gear, Micro formin Die