A complete micropositioning unit based on high precision, manually controlledX‐Y‐Ztranslators, related metrology system, and sighting microscope is described. It has been specifically developed for the alignment of collimating pinholes (5–10 &mgr;m diam) on cryogenic x‐ray detectors, 10–50 &mgr;m in size, deposited both on transparent and opaque substrates. The main characteristics of this flexible and convenient system are the capability to handle a complete test fixture ready for further measurements at cryogenic temperature, coupled with the possibility to verify the precision attained. Such microalignment equipment will find application in optical/UV/x‐ray photon counting experiments, whenever a highly collimated illumination is required or in any test involving precision positioning of small experimental units onto microdevices or detectors.