© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. This study was performed to investigate the effectiveness of dexamethasone in the management of postpartum women with class 1 haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome. This retrospective study was conducted on 18 women with class 1 HELLP syndrome at the Shiga University of Medical Science. They were divided into two groups: Group A comprised participants who did not receive dexamethasone, and Group B comprised participants that intravenously received dexamethasone. The main outcomes were the serum laboratory values, mortality and morbidity. The only significant difference between the two groups in baseline characteristics was the aspartate aminotransferase levels. The linear regression analysis showed a significant difference between the two groups in the recovery of platelet counts (p =.046) and aspartate aminotransferase (p =.009). These findings support the use of high-dose dexamethasone to promote recovery of the platelet counts and aspartate aminotransferase levels in postpartum women with class 1 HELLP syndrome.Impact statementWhat is already known on this subject? Haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome is one of the most dangerous complications that can occur during pregnancy and is considered a particularly serious variant of severe preeclampsia. Several clinical trials have been performed since 1994 because it was expected that corticosteroid therapy, primarily with dexamethasone, accelerates recovery after delivery. However, the effect of dexamethasone therapy on class 1 HELLP syndrome is unclear. What do the results of this study add? In this retrospective study, we demonstrated that dexamethasone administration significantly improved the recovery of the platelet count in postpartum women with class 1 HELLP syndrome, and did not increase the rate of maternal postpartum complications. What are the implications of these findings for clinical practice and/or further research? The use of high-dose dexamethasone in postpartum women with class 1 HELLP syndrome might be effective to promote recovery of the platelet count, and contributes a shorter duration of hospitalisation. Because the number of patients with class 1 HELLP syndrome is small, it is important to confirm these findings with well-designed multicentre prospective studies.