The agency secured the business following a pitch against CHI & Partners, Bartle Bogle Hegarty, Kitcatt Nohr Alexander Shaw, Beattie McGuinness Bungay and Isobel. The pitch was mediated by Haystack.
Richard Hodgson, the retailer's buying director, made the appointment.
Jeremy Miles, chairman of MCBD, said: "We're delighted to have retained the Waitrose business against London's finest competition. It's one of the country's great brands and we're looking forward to a long and fruitful relationship."
MCBD secured the Waitrose account in 2005, when it acquired HOW, the retailer's then incumbent agency. Since then it has produced multiple commercials about Waitrose's ethical sourcing and partnership status.
A Waitrose spokeswoman said: "Following a comprehensive review of the Waitrose brand and advertising business, the company has decided to retain the services of MCBD. The standard of work received by Waitrose was exceptional and the company is now confident that it has a platform to support its future business growth."