Graham Dives's wife Jenny was looked after by Thames Hospicecare (THc) for six days before her death from oesophageal cancer a year ago.
She was cared for by ward sister Rosemary Webb and her team of nurses at Pine Lodge Hospice in Windsor.
Graham, 66, from Priestwood, said: "It's very difficult to express in words the love, care and affection that Jenny received from Rosemary and all the nurses at the hospice.
"It was as if she was their only patient. But that care was also extended to my daughter Sarah and me not just during the time Jenny was cared for, but since.
"The walk is one way I can show my gratitude."
He is doing a seven-mile walk but there is also the option for a 13-mile route, both starting at Windsor Boys School, Maidenhead Road, Windsor, on Saturday, July 2.
Rosemary said: "We're very touched by Graham's kind words. Our job is to help our patients live their life to the fullest as best they can and to help and support their families at probably the most difficult time, caring and coping with a loved one who is dying.
"In the same way that Graham appreciates us being here for Jenny, Sarah and him, we're also glad that we have him supporting our work and ensuring that we can continue to be here for many more families."
The hospice charity supports people in their homes, at its day centre in Kings Ride, Ascot and at its hospice in Windsor. It also tries to help families and carers and offers bereavement care. Entry to the THc Midnight Walk is £15 and the hospice asks participants to raise as much as possible in sponsorship, with a prize for the person who raises the most. All walkers will receive a medal and goody bag at the end.