Purpose: Patients presenting with leukaemic blast crisis with acute myeloid leukaemia (AML) may have gingival enlargements that interfere with oral hygiene. Few large cohort studies of gingival lesions have been carried out on AML patients. The aim of the present study was to assess gingival and periodontal pathology at the time of presentation, prior to chemotherapy, in a cohort of adult patients presenting at a cancer hospital in Kerala, a region located in southern India. Materials and Methods: A total of 73 young adult patients (mean age 20.6 ± 2.3) who were diagnosed with AML were examined. These patients did not suffer from any other systemic disorder. The oral hygiene status, gingival overgrowth (GO) and periodontal status were assessed using traditional clinical indices. Results: Around three-quarters of the patients had either fair or poor oral hygiene. A statistically significant association between dental plaque levels and both GO and periodontal index (P 0.001) was observed. Conclusions: Poor oral hygiene is a risk factor for leukaemic GO and for destructive periodontal disease. Both conditions add to the microbial burden these patients are exposed to. In patients showing high levels of oral hygiene, the GO tends to be mild and does not seem to be problematic, especially with respect to mechanical tooth cleaning. Keywords: acute leukaemia, dental calculus, dental plaque, gingival overgrowth, oral hygiene