Hundred of patients signed a book of thanks for Juan Martinez, who worked at the Hart Surgery in York Road.
The 44-year-old is returning to the village surgery in Mortimer, near Reading, where he trained as a GP.
Dr Martinez, who lives in Peppard Common, was a partner in the surgery and was responsible for making business decisions.
He said he wanted to go back to a more hands-on role as he was happiest when helping patients.
On his final day last Friday, colleagues baked him a cake and presented him with the book, which they began compiling in June.
Dr Martinez said: “It has been a very hard decision for me as I am very attached to my patients.
“The past few weeks have been very emotional and I have been overwhelmed by all the comments my patients have made about me. I shall miss them very much.
“It’s hard to think of any particular highlights but it has been a privilege looking after the people of Henley and being a part of their lives. I will obviously miss my colleagues but it is the patients I will miss the most.”
Dr Martinez grew up in Bilbao and obtained a postgraduate qualification as a doctor in the UK.
He spent a year as a trainee GP at Mortimer and they recommended him for the job in Henley.
On top of his duties at the surgery, where he looked after 2,000 of its 10,000 patients, he worked on Peppard ward at Townlands Hospital.
He was also medical officer at Huntercome Hall care home in Nuffield.
He will continue to live in the area with his wife Andrea and children Pablo, Amaia and Ioan. As well as messages of thanks, some in Spanish, his leaving book contains crayon drawings by some of his younger patients.
One message thanked him for his “endless, wonderful care and compassion” and another simply said: “You’re a legend”.
Dr Martinez said: “It really is fantastic to look at all these comments. It makes you realise what being a doctor is all about.
“When I got the job I wasn’t sure if I’d fit in as a Spanish doctor in Henley but it has felt like home from day one.
“I’m always bumping into people I recognise in the street. I feel like part of the community and that’s what I will miss the most.”
Dr Philip Unwin, the surgery’s senior partner, said: “Juan is a very good doctor and an extremely nice chap, so it’s sad that he is leaving.
“He is going to leave behind a lot of patients who will miss him.”