The aim of this study was to standardize a Loop-Mediated isothermal Amplification (LAMP) assay for the detection of the Philippine isolate of Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) in postlarvae of shrimp, Penaeus monodon. The assay was optimized at an incubation time of 1 h at 63^oC. The assay was highly specific for IHHNV and did not cross-react with other shrimp viruses including Hepatopancreatic Parvovirus (HPV), Monodon Baculovirus (MBV) and White Spot Syndrome Virus (WSSV). The limit of detection of the IHHNV using the LAMP assay was 10 pg of DNA/mL or 10 fg of the genomic DNA per LAMP reaction and was 10 times more sensitive than conventional PCR in detecting the viral pathogen from infected samples. These results demonstrated that LAMP is a simple and sensitive diagnostic technique that has potential application for routine detection of IHHNV infections in shrimp hatcheries in the Philippines.