In mainland France, the estimated number of new cases of chronic myelomonocytic leukemia (CMML) and other myelodysplastic syndromes/myeloproliferative syndromes (MDS/MPS) in 2018 was 1,439, including 853 cases in men and 586 cases in women. Key points: Intermediate prognosis with a 5-year age-adjusted net survival rate of 45% for individuals diagnosed between 2010 and 2015; 5-year net survival decreases with age at diagnosis: 52% at age 60 versus 32% at age 80; Higher 5-year net survival in women, regardless of age at diagnosis (between 9 and 10 percentage points higher than in men); Slight improvement in 1-year standardized net survival between diagnoses in 2005 and those in 2015 (+4 percentage points) but stability in 5-year and 10-year standardized net survival.