Background: Since the aim of healthcare research is improved patient care, a lack of detail in describing an intervention in a trial or systematic review will limit the extent to which research can influence practice. Hence, we aimed to assess whether (i) the details of treatment interventions are sufficient to allow most clinicians to reproduce the treatment, and (ii) if reproducibility can be improved by writing to authors, checking references, and internet searches. Methods: For 80 studies selected for the EBM journal, two general practitioners assessed whether they could reproduce the treatment. If information was missing, we retrieved cited papers relevant to the treatment description, wrote to study authors, and searched the internet. Results: Of the 80 reports, 49% (39/80) had an adequate treatment description: 65% (36/55) of randomized trials and 12% (3/25) of systematic reviews. This proportion was improved to 76% by checking references, responses from authors, and searches (see Table 1 on next page). Problems with treatment descriptions included missing information on timing and dosage, on technique, and on access to educational and training materials used in studies. A description of the 80 studies shows whether treatment descriptions were rated as having a sufficient treatment description (i) initially (based only on the published paper) (ii) after writing to authors and obtaining supplementary information. Conclusions: For a high proportion of the reports of trials and systematic reviews, the description of the treatment is often insufficient to permit a clinician to reproduce the treatment in practice. However, provision of some additional details could improve the proportion of treatments that clinicians could reproduce in practice. Current inadequate treatment descriptions represent a waste of research resources and a lost opportunity to improve patient care.