Abstractobjective In 4-to 8-year-old Zambian children (n = 744), we evaluated the effects of adjusting for inflammation (a1-acid glycoprotein >1 g/l), with or without additional adjustment for malaria, on prevalence estimates of iron deficiency (ID) and iron deficiency anaemia (IDA) during low malaria (LowM) and high malaria (HighM) transmission seasons.methods To estimate adjustment factors, children were classified as: (i) reference (malaria negative without inflammation), (ii) inflammation without malaria (I), (iii) malaria without inflammation (M) and (iv) inflammation with malaria (IM). We estimated the unadjusted ID or IDA prevalence, and then adjusted for inflammation alone (ID I or IDA I ) or inflammation and malaria (ID IM or IDA IM ).results Mean ferritin was 38 (reference), 45 (I), 43 (M) and 54 lg/l (IM) in LowM, increasing to 44, 56, 96 and 167 lg/l, respectively, in HighM. Corresponding mean sTfR was 6.4, 6.9, 7.9 and 8.4 mg/l in LowM, increasing to 8.2, 9.2. 8.7 and 9.7 mg/l in HighM. Ferritin-based ID, ID I and ID IM were 7.8%, 8.7% or 9.1%, respectively, in LowM and 4.6%, 10.0% or 11.7%, respectively, in HighM. Corresponding soluble transferrin receptor (sTfR)-based estimates were 27.0%, 24.1% and 19.1%, respectively, in LowM, increasing to 53.6%, 46.5% and 45.3%, respectively, in HighM. Additional adjustment for malaria resulted in a~1-to 2-percentage point change in IDA, depending on biomarker and season.conclusions In this population, malaria substantially increased ferritin and sTfR concentrations, with modest effects on ID and IDA prevalence estimates.