Comamonas kerstersii (C. kerstersii) infections have considered as non-pathogenic to humans, however due to new techniques such as matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS), more cases have been identified.This is the first report of a maternal patient with a C. kerstersii bacteremia following caesarean section. Due to the severity of the patient's condition; high fever and rapidly progressing organ damage, the patient was transferred to the intensive care unit. C. kerstersii was detected by metagenomic next-generation sequencing testing. Based on the drug sensitivity test, appropriate antibiotic treatment was given and the patient recovered fully.This case report confirms that the detection via MALDI-TOF-MS and metagenomic next-generation sequencing testing provides a reliable basis for the diagnosis of this rare bacterial infection.©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.