Background:  Over 2.6 million babies are stillborn every year mostly in low‐ and middle‐income countries, where cause of death remains often unexplained.

Aim:  To determine the applicability and utility of the Perinatal Society of Australia and New Zealand (PSANZ) Clinical Practice Guideline (CPG) for Perinatal Mortality in reducing the proportion of unexplained stillbirths in a hospital setting in Vietnam.

Methods:  An analytic cross‐sectional study of stillborn babies born at a major maternity facility in Vietnam. Maternal history, external physical examination of the baby and placental macroscopic examination were performed. Two experienced classifiers independently assigned PSANZ perinatal death classification (PDC). This was compared to cause of death documented in the hospital records.

Results:  107 stillborn babies were born to 105 mothers. The proportion of stillborn babies classified as unexplained was reduced from 52.3 to 24.3% (P < 0.01) using the PSANZ–PDC system. Causes of death were congenital abnormalities (35.6%), hypertension (8.4%), fetal growth restriction (8.4%), specific perinatal conditions (8.4%), spontaneous preterm (6.5%), maternal conditions (5.6%) and antepartum haemorrhage (3.7%). Conclusions:  Application of the PSANZ–CPG and stillbirth classification system is effective and feasible in a low‐income country facility setting and resulted in a reduction in the number of babies classified as unexplained stillbirth in Vietnam.