Three new species of Camelobaetidius Demoulin (Ephemeroptera : Baetidae), C. hamadae sp. n., C. lassance sp. n., and C.
maranhensis sp. n., are described based on nymphs from Brazil. Some of the diagnostic characters of the new taxa are : C. hamadae
sp. n., two thoracic gills at base of forelegs and claws with 36-37 denticles ; C. lassance sp. n., claws with approximately
60 denticles and posterior margin of terga with few, large and elevated spines ; C. maranhensis sp. n., pronotum with medial
pair of tubercles and terminal filament shorter than 10th abdominal segment. Camelobaetidius cayumba (Traver & Edmunds),
C. matilei Thomas & Perú, and C. tuberosus Lugo-Ortiz & McCafferty, are recorded for the first time from Brazil. A key to the
species of Camelobaetidius recorded from Brazil based on nymphs is presented.