This paper is a brief analysis of the parameters required for an adequate process of monitoring and measurement of harmonics in electric power networks for power quality studies. Initially, basics of harmonics in electric power networks are introduced; subsequently, standards and recommendations for quality control of electrical energy in the Colombian context are mentioned. Following this some important points to be taken into account for the appropriate acquisition and processing of the voltage and current signals in both fundamental frequency and harmonic frequency, are presented, where the emphasis is on issues such as: harmonic measurement, determination of point of common connection (PCC), proper placement of the sensors and storage data equipment, power quality measurement, frecuency of sampling, observation intervals, transducers, voltage harmonics measurement, current harmonics measurement and system conditions for measurement.