AbstractIntroduction: Neonatal Intensive Care Units (NICUs) have a high rate of nosocomial infections. Invasive fungal infections are increasingly being reported from ICUs. Trichosporon asahii is an uncommon emerging cause of sepsis and life-threatening opportunistic pathogen. The present study was to investigate the epidemiological factors related to invasive infection by Trichosporon asahii among neonates in a tertiary care hospital in Delhi. Methods: Seven isolates of Trichosporon asahii were reported from routine blood cultures (BacT/ALERT) during a period of two and a half months. Identification and Antifungal Susceptibility testing was done by Vitek 2 Compact System. Outbreak investigations and infection control measures were initiated after the detection of 3rd case. Forty five samples from environment and health care workers were collected and processed to find out the source and infection control measures were strictly implemented. Results: A total of 7 cases of fungemia by Trichosporon asahii occurred in neonates that were mostly preterm and low birth weight. All of them were on broad spectrum antibacterial agents. Environmental samples were positive for this fungus from I.V. cannulae of 4 neonates out of which one developed infection. Strict implementation of Infection control practices resulted in cessation of the outbreak. Conclusion: The exact source of infection could not be identified. However, the epidemiology of the disease was pointing towards an exogenous source and spread through hands of HCWs. Use of broad spectrum antibacterial agents, preterm and low birth weight were predisposing factors. The strict and prompt actions taken to control the outbreak were fruitful showing that breach in infection control practices resulted in the outbreak.