A former BT executive was found at the pub after killing his wife's at the couple's £1.6 million south-east London home.
Leslie Winnister, 68, pleaded pleaded guilty to the manslaughter by diminished responsibility of 66-year-old Suzanne Winnister in Bexley.
The victim was discovered by family members at the couple's home in Becketts Close on the evening of September 8 last year.
She was pronounced dead at the scene after police and paramedics arrived.
Winnister was later found in a nearby pub.
A post mortem gave Mrs Winnister's cause of death as head and neck injury.
The victim had previously had a career in banking but was retired by the time of her death.
At a plea hearing at the Old Bailey yesterday Winnister entered a guilty plea to manslaughter on the grounds of diminished responsibility.
Psychiatric reports for both the prosecution and the defence concluded that a defence of diminished responsibility was available, the court heard.
Winnister, who is being treated at the Bracton centre medium secure unit in Dartford, was accompanied in the dock by two nurses.
Judge Wendy Joseph QC remarked it was "a sad case".
Listing the case for sentence on June 25, Judge Joseph warned Winnister that a wide range of options were available to the court, from prison to a psychiatric hospital.
Several members of the Winnisters' family were seated in court, as well as some friends.
Locals told the Mail Online they had been shocked by the death.
Neighbours said Mrs Winnister was 'always looking out for others'.
Retired sports marketing chief Perry Smith descried Mr Winnister as "a really nice guy" who would work long hours at a job that appeared to cause him a lot of stress.
He added: "Les and Sue were just a very nice, respectful and friendly couple. She was short but had quite a dominant personality – the tough one out of them. She was the boss. It's so tragic what's happened – it's such a shock.
"I last saw Les around a month ago. I asked him how he was and he said, 'I'm very well, thanks'."
