The 34-year-old former British Army captain began his journey in Camana, Peru, in April, 2008, to raise awareness of deforestation. He tweeted and blogged along the way using a satellite video phone and a laptop.
He travelled more than 6,000 kilometres alongside the Amazon River from source to mouth, beginning from the summit of Nevado Mismi in Peru and ending at Crispim Beach in Brazil.
Floods forced the trekker inland and added more than 3,000 extra kilometres to his route, bringing his total to almost 10,000 kilometres.
Other than the rafts he sometimes used to cross rivers, Mr. Stafford travelled completely by foot.
Mr. Stafford started out his journey with co-traveller Luke Collier, but the pair had a falling out - reportedly about an MP3 player - and Mr. Collier left the expedition after three months.
"If I'm honest, at this stage the hardest thing has been getting on well with Luke and finding our feet with each other," Mr. Stafford wrote on www.walkingtheamazon.com in July, 2008.
Mr. Stafford was joined shortly after by Gadiel (Cho) Sanchez Rivera, a Peruvian forestry worker who stayed with him for the rest of his trek.
Mr. Stafford took it all in stride as he suffered from a painful skin disease, fainted from exhaustion and experienced fluid retention in his knees and elbows.
"My bizarre swollen knee is back and now my elbow is full of fluid too!" he tweeted on July 4. "No pain - so no problem - just a bit odd."
But one health problem got under his skin - literally.
"A botfly is living in my head and keeping me awake by eating me," Mr. Stafford tweeted on July 6. "Hopefully killing and extracting it this morning."
Botflies lay their eggs on mosquitoes, which then bite animals - or humans - and lay the botfly eggs under the skin. In Mr. Stafford's case, it took a tree needle and a tube of Super Glue to extract the insect. In his video blog of the event, Mr. Stafford moans as the maggot-like bug is pulled from the back of his head.
Encounters with locals
From being personally escorted by a tribal chief for 47 days through hostile territory to being chased along a riverbank by five boats full of arrow-wielding villagers and accused twice of murder, Mr. Stafford has had his ups and downs when it came to the locals he met during his two-year journey.
Such as the time in October, 2008, when Amazonian villagers forced concrete into his mouth and threw buckets of watered-down concrete at him.
"They clearly think I'm a gringo who's coming in here to prospect for oil," he said in a video blog as he walked through the jungle pasted with grey, cracking concrete. "I'm absolutely drenched with concrete-water."
Mr. Stafford said later in the video that he went through official channels to get permission to cross territories.
Encounters with animals
Howler monkeys fill the trees in the Amazon, vipers and anacondas hide under rocks and branches on the jungle floor and the water is full of electric eels and piranhas. Mr. Stafford encountered all of them along his way.
On March 11, he blogged that he had stumbled upon a three-metre snake beside a flood plain.
"Rather than dart away from me the brave snake seemed interested, splayed its neck wide like a cobra, and headed towards me," he wrote.
He has also said he's been bitten by mosquitoes 50,000 times and experienced hundreds of wasp stings.
"A wasp attack at any time isn't welcome but straight after breakfast is just rude," he tweeted in April. "Six stings. Bad start to the day!"
What's next
Mr. Stafford returns home to Leicestershire, Britain, on Aug. 11. He's hinted that he has another adventure planned for 2011, but hasn't said what that may entail.
He has said he plans to work on a book about his adventure.
"Book coming in spring 2011 …" he tweeted in June.
For now, he'll rest.
"I'm more tired and more elated than I've ever been in my life," he said Monday. "We've lived through some very serious situations and there have been times when we genuinely feared for our lives, but we never ever thought of giving up."
The Amazon journey by the numbers:
Countries crossed: three
Days spent walking: 859
Length of the Amazon River: about 6,800 kilometres
Total distance travelled: about 9,800 kilometres.
Detour due to flooding: about 3,000 kilometres
Elevation of Nevado Mismi: 5,597 metres
Cost of journey: about $100,000 (U.S.)
Major sponsors: at least 22
Mosquito bites: about 50,000
Weight lost: 15 pounds
Shoes destroyed: Four pairs of Crocs, three pairs of hiking boots and two pairs of rain boots
Hours worth of powdered anti-venom carried at all times: 48
Hours it can take to bleed to death after a viper bite without anti-venom: three
Hours held in a hut under suspicion of murder: 24
Times accused - wrongly - of murder: two
Numbers of sloth rescued from flood waters: one
Botflies nested in back of head: one