The prevalence and nature of resident teaching skills improvement programmes (TSIP) are unknown. Although residents perceive themselves as important teachers of students, there is little information on how programme directors (PDs) view residents as teachers. A comprehensive questionnaire was sent to all 428 US internal medicine PDs in December 1990, of which 60% (n = 259) responded. Of the 259 responding programmes, only 20% (n = 51) had TSIPs. Characteristics of TSIPs were not uniform. Mean instructional time was 9 hours (range, 1-24 hours). The teacher most frequently utilized to develop and facilitate the TSIP was the PD. PDs from residencies with a TSIP indicated more strongly than PDs without a TSIP that residents contributed to students' learning. Fifty-one per cent of TSIPs required residents to attend. Evaluation/feedback as a teaching method was the most common topic covered in TSIPs. Long-term assessment of teaching skills after programme participation was done in 15% of TSIPs. Although PDs value the resident's role as teacher, current TSIPs in internal medicine residencies are few in number and lack standardization. PDs' attitudes probably influence whether residents are taught teaching skills and whether teaching skills are evaluated. Further investigation of appropriate curriculum for TSIPs and assessment of long-term effectiveness of TSIPs are needed.