Scope's head of fundraising Aneesha Moreira is moving to the British Heart Foundation next month.
Moreira, who is on annual leave, is joining the British Heart Foundation as director of donor fundraising.
She has spent five years with the cerebral palsy organisation, joining as a general manager.
She now heads a 70-strong fundraising team and has worked through a period of significant change at the charity, following spending cuts of £4 million at the end of 2000 that were partly due to plummeting shop profits.
Prior to Scope, Moreira worked at Help the Aged, where she was fundraising manager.
Scope is conducting the first round of interviews on 9 October to find a replacement for Moreira.