Sequential scintigraphy enables the qualitative and quantitative study of the drainage function of the Eustachian tube. Use is made of serum albumin labeled with technetium 99 m. After reviewing the various methods employed in an exploration of the functions of the Eustachian tube, and in particular the drainage function, the writers explain the method in detail (indicator, detection system, examination procedure, normal scintigraphic aspects) while stressing the control factors (onset of passage, speed and intensity of passage, length of time for the appearance of a trace on the pharynx, eventual aspects of blocking) and giving the basic characteristics; persistant spotting of the drum, transient image of the tube, partial stoppage at the ostium, and traces along the pharynx. The role of swallowing and the position of the head appear to be essential. Results obtained in various disorders of the middle ear, accessory cavities, the tube and the cavum are given in the form of tables. The writers then indicate the principal merits of the method: demonstration of the pathological role of the Eustachian tube in a work-up of transmission deafness, with its impact on treatment, the role of a deficient drainage function in surgical failures, and control of the efficacy of treatment, in particular crenotherapy. A study of the drainage function of the Eustachian tube, as a complement to the function of equalizing pressure, in an essential factor in formulating indications and in establishing the prognosis for tympanoplasties.