Land registration and cadastral surveying always need field measurements with proper standards and sufficiently precise instruments. Since more than two decades in Iran, handheld GPS receivers are used for these purposes. Presently, positioning accuracy with handheld receives is not better than 3m. However, some official experts in the matter, use handheld and smartphone GPS receivers for legal land surveys. In this paper, we investigate the accuracy and precision capacities of standard surveying techniques and compare them with those of handheld GPS receivers. Inconsistencies produced in the land parcel’s position as well as in its geometric setup including lengths and area are investigated. Satellite and terrain based standard surveying methods are applied to measure the positions of vertexes of a land parcel of about 4500 m2. Its geometry is then determined with a few millimeters’ accuracy and the reference values for lengths and area are derived. The results of 78 measurements carried out with handheld GPS receivers are then compared with the reference values. Differences up to 20m in position and 1000m2 in area are occurred with reference values measures with precise surveying method. These comparisons testify that the use of handheld GPS receivers causes sever legal problems and the authorities should prevent their use for official land surveying purposes.