The authors recall the fundamentals of an adequate use of the X-rays considering to the ALARA (As Low As Reasonably Achievable) principle. The article deals more specifically with radiation protection and quality control in radiopediatrics, as this age group is essentially concerned with stochastic hazards, i.e. cancer induction and genetic injurious effects. The major elements of X-ray equipment are reviewed, including the X-ray generator, device, film-screen, radiogenic tube, automatic exposure device, and so on... The influence of technical parameters on dosimetry in terms of radiation protection as well as dosis variation, according to the type of disorder, are demonstrated. Reference is made to the radiologic techniques proposed by the Lake Starnberg Group.