The documentation of illness-related data, e.g. repetitive recordings of pain parameters, medication or mood, is commonly accomplished by the use of questionnaires. Several disadvantages for both the patient and experimentor related to this method can be avoided by the application of specially designed data-loggers. The use of commercially available portable pocket computers is usually complicated because of the miniature full-range keybords. This paper describes a completely new design, which relies on the use of only four keys. All operations are imaged on an LCD display (4 lines with 16 signs). The Rating Box allows the presentation of visual analogue scales (VAS) of different step widths, movement of cursors, forced choice and multiple choice decisions, as well as the input of decimal numbers. Up to 11 scale types can be deliberately combined in a series of up to 27 items. The combination can be individually designed and edited by the experimentor. The results are stored together with the input time and date. Actual inputs are not influenced by comparison to earlier input, since data recall can only be accessed by the experimentor. The use of the Rating Box by a patient is called up by signal tones at individually given times of day. Additional inputs are possible when required. Warnings are presented for general malfunctions. The results can be transmitted to a personal computer and processed statistically or to daily or weekly profiles of mood, pain or disability scores, for example. A pilot study in elderly patients (42–76 years) with pain due to cancer gave promising results. The Rating Box was well accepted as opposed to a questionnaire. Nine out of 12 patients preferred the Rating Box both methods were judged to be equivalent by two patients and only one regarded the use as difficult and thus preferred the questionnaire. In addition, 5 out of 12 patients confessed by inquiry to have filled in the questionnaire forms retrospectively. This possibility is in principle excluded by the Rating Box.