[How painful is intensive insulin therapy?]. Injection-pain was assessed in 39 type-1 diabetic patients in relation to an insulin injection (with an insulin-pen) into the upper arm, the abdomen, and the thigh and in another 10 patients, pain associated with finger-pricking for blood-glucose self-monitoring was assessed. Pain perception was recorded on a visual analogue scale. According to the results, injections were relatively painless with an average (median) pain-score of less than 10% of maximum pain. Injection pains varied in relation to the injection sites (upper arm greater than thigh greater than abdomen). Least painful (n = 44) versus most painful (n = 39) injections were distributed as follows: upper arm 20% vs. 46%, abdomen 43% vs. 23%, thigh 36% vs. 31% (chi 2 7.26, df2, p less than 0.05). Finger-pricking was no more painful than injecting insulin. It is concluded that insulin injecting (e.g. with insulin pens) and blood glucose self-monitoring in general is not very painful. However, if this positive conclusion also applies to long-term performance of intensive insulin therapy remains to be proven.