Docherty (31) won the silver medal behind fellow New Zealander Hamish Carter in Athens in 2004 and the bronze medal in Beijing this year. He wants the gold medal to complete the set.
"I've left the hardest till last. It's the only one that's eluding me," Docherty told the Otago Daily Times yesterday.
"One good thing about winning silver and bronze is that there is still a goal at hand. It will keep driving me on for another four years and get the best out of me."
Docherty was in Dunedin on a promotional tour for Triathlon New Zealand and spoke to pupils at various secondary schools and the Dunedin Triathlon Club.
Docherty would probably have have carried on to London even if he had won the gold medal at Beijing?
"I'm still enjoying the sport," he said.
"To be honest I don't want to get a real job. I probably would have kept going."
Although the gold medal has eluded Docherty he is still one of a few New Zealand athletes to have won medals at back-to-back Olympics.
"I was very happy with Beijing," he said.
"I won medals at two Olympics and that is why I was happy."
The hardest part of the Beijing experience for Docherty was the 18 months of strenuous training beforehand.
"I wanted to front up at the start line in the best possible shape," he said.
All Docherty's training during the next four years will be focused on the London Olympic Games. But he is also happy with the major new developments in triathlon that start next year. This includes a series throughout New Zealand this summer and a new World Cup series as well.
"There used to be a one-off world championships but they have now turned it into a six-race series," Docherty said.
"There should be better money for the competitors, better coverage in the media and more competitive fields."
Docherty has been coached by Wanaka coach Mark Elliott for the past decade.
"Mark's had a big influence on my career," Docherty said.
"He's a fantastic guy and everyone respects him.
We know the formula and work very well as a team"Docherty grew up in Taupo, but these days as a professional triathlete he spends six months of his year based in high-altitude Colorado and the other six months in Auckland.
Docherty has committed himself to spending four more years in the sport but was not prepared to predict his future after that.
