Welsh Rugby Union (WRU) chief executive Abi Tierney will step away from her role after being diagnosed with cancer.
Tierney will take time away from her duties from 22 August to undergo treatment, with no return date given.
“This has not been an easy decision, but it is one I must make to focus fully on my health and recovery,” she said.
“I am grateful for the support I have already received from my family, friends, and colleagues, and I am confident in the team’s ability to continue our work during my absence.
“I kindly ask for understanding and privacy during this time.”
Chair Richard Collier-Keywood will take temporary overall charge of the governing body.