Abstract: This study was aimed to evaluate the effect of administering biscuits enriched with albumin protein from snakehead fish, zinc and iron on immune response of under five children. This was pre-post, single blind, randomized control trial conducted in twenty eight preschool children aged 4-5 year attending Early Childhood Education (PAUD) in Pilar village, sub-district of Semplak, Bogor Regency, West Java. The children were randomly assigned to experimental group which receive biscuit with protein source from snakehead fish flour fortified with zinc and iron and control group which receive biscuit with protein source from milk. Both biscuits had a similar on protein and energy content of 13.34% and 503 kcal, respectively. A 60 g biscuits per day was consumed by the children for 56 days. Results showed that experimental biscuits (biscuits sourced snakehead fish protein) had a higher contribution on energy, protein, Zn and Fe than a control biscuits (biscuits sourced milk protein). Fish biscuit contribution to energy was 14.64% RDA, protein was 14.75% RDA, Zn was 53.52% RDA and Fe was 39.26% RDA. Milk biscuit contribution to energy was 9.40% RDA and protein was 4.29% RDA, Zn was 3.27% RDA and Fe was 5.80% RDA. T-test result showed that milk biscuit group was significantly different (p<0.05) than fish biscuit group on nutrient intakes and contribution to energy, protein, Zn and Fe RDA. Immunoglobulin (IgG) mean increase at the end of the study in fish biscuit group was higher, which was 0.88±0.58 mg/mL compared to milk biscuit group which was decreased by -60.31±81.76 mg/mL. Increase of albumin mean at the end of the study in fish biscuit group was higher, which was 0.48±0.32 g/dL compared to milk biscuit group which was 0.05±0.13 g/dL. T-test result showed that IgG and albumin difference in fish biscuit group was significantly (p<0.05) than milk biscuit group.