The aim of the present investigation was to study the effect of daily plaque removal on gingival inflammation and the occurrence of oral mucosal ulcers in granulocytopenic patients with acute myeloid leukemia. Eleven patients were analyzed prospectively and consecutively during a period of 28 days, in which the patients were treated with antineoplastic drugs. The patients had their teeth scaled, and plaque was removed daily. On Day 1 all had gingival inflammation, and two had profound periodontitis with pocket depths and loss of attachment greater than 5 mm. During the treatment period plaque scores were reduced in all patients and a corresponding decrease in gingival inflammation was seen. It was possible to obtain healthy gingiva during treatment with cytotoxic drugs. In addition, the development of oral mucosal lesions was low compared with other studies. This study demonstrates that daily plaque removal from the teeth resolves gingival inflammation also in severely granulocytopenic patients.