The USA duo are the only back-to-back Olympic champions in Beach Volleyball history following their triumphs at the Athens 2004 Games and in Beijing four years later.
Those triumphs were completed without losing a match or even a single set, but much has changed since their famous win in the rain in Beijing, with May-Treanor out for a long spell with an Achilles injury and Walsh giving birth to two children.
And with teams from Brazil and China poised to offer stern competition, a third gold medal-winning performance would surely rank as their finest achievement.
The duo can expect to have a better idea of their prospects tomorrow, when they are due to finish their opening pool phase match against former Olympic champion Natalie Cook of Australia and her partner Tamsin Hinchley.
But whatever the outcome, 34-year-old May-Treanor is simply determined to enjoy the experience.
'Kerri and I, we want obviously to go for number three, nobody's done it before,' said May-Treanor. 'For me, this is my last Olympics so I'm going to enjoy the journey, every practice, every time I'm on the sand. I'm going to take everything in.'
Six-time women's world champions Larissa Franca and Juliana Felisberta Da Silva of Brazil will also be in action on the opening day, taking on Natacha Rigobert and Elodie Li Yuk Lo of Mauritius.
Elsewhere, Beijing bronze medallists Xi Zhang and Chen Xue will have the honour of contesting the opening match of the tournament when they play Russia's Anastasia Vasina and Anna Vozakova.
The eye-catching opening-day match in the men's competition sees British pair John Garcia-Thompson and Steven Grotowski open their campaign against Canada's Josh Binstock and Martin Reader.
Elsewhere, Brazilian great Ricardo Santos begins his bid for a fourth Olympic medal - following on from his silver at Sydney 2000, gold at Athens 2004 and bronze at Beijing 2008 - when he and team-mate Pedro Cunha play Norway's Tarjei Skarlund and Martin Spinnangr.
USA duo Todd Rogers and Phil Dalhausser will start the defence of their title on Sunday when they play Japan's Kentaro Asahi and Katsuhiro Shiratori.
The top seeds in the men's draw are Brazilian duo Emanuel Rego and Alison Cerutti, who also begin their campaign on Sunday.