A monosomal karyotype (MK), defined as ≥2 autosomal monosomies or a single monosomy in the presence of additional structural abnormalities, was recently identified as an independent prognostic factor conveying an extremely poor prognosis in patients with acute myeloid leukemia (AML). In the present study, after excluding patients with t(15;17), t(8;21), inv(16) and normal karyotypes, 324 AML patients with cytogenetic abnormalities were the main subject of analysis. The incidences of MK were 13% in patients aged 15 to 60 years and 18% in those between 15 and 88 years old. MK was much more prevalent among elderly patients (p<0.001) and was significantly associated with the presence of -7, -5, del(5q), abn12p, abn17p, -18 or 18q-, -20 or 20q- and CK (for all p<0.001 except for abn12p p=0.009), and +8 or +8q was less frequent in MK+ AML(p=0.007). No correlation was noted between monosomal karyotype and FAB subtype (p>0.05); MK remained significantly associated with worse overall survival among patients with complex karyotype (p=0.032); A single autosomal monosomy contributed an additional negative effect in OS of patients with structural cytogenetic abnormalities (P=0.008). This report presents the prevalence, feature and prognostic impact of MK among a large series of Chinese AML patients from a single center for the first time.