To examine Hb level and anaemia status among infants under 6 months of age in rural China.

A cross-sectional survey collected data among infants under 6 months and their primary caregivers in Sichuan, China. Anaemia was defined using both the WHO and China Pediatrics Association thresholds. Multivariable linear regression was used to identify relevant factors among two age groups (<4 months; 4–5 months).

Eighty townships were selected in Sichuan, China from November to December 2019.

Nine hundred and forty-two infants under 6 months, while Hb level was tested for 577 infants.

The overall mean (±sd) Hb level was 106·03 (± 12·04) g/l. About 62·6 % (95 % CI 58·5, 66·6) of sample infants were anaemic using the WHO threshold, and 20·5 % (95 % CI 17·3, 24·1) were anaemic using the China Pediatrics Association thresholds. Anaemia rates rose with increasing age in months. Multivariable linear regressions revealed that lower Hb levels were significantly associated with lower birth weight (<4 months: β = 4·14, 95 % CI 0·19, 8·08; 4–5 months: β = 6·60, 95 % CI 2·94, 10·27) and delivery by caesarean section (<4 months: β = −4·64, 95 % CI −7·79, −1·49; 4–5 months: β = −4·58, 95 % CI −7·45, −1·71).

A large share of infants under 6 months in rural western China are anaemic. Infants with low birth weight and caesarean delivered should be prioritised for anaemia testing. Future studies should move the point of focus forward to at least 4 months of age and examine the link between caesarean section and anaemia to promote health and development in infancy.