The risk of dying within 30 days following an operation was 12 per cent less if a woman operated. There was no significant difference in readmissions to hospital or complications.
Dr Raj Satkunasivam said "Women and men practise medicine differently, although little research exists on the differences in learning styles, acquisition of skills, or outcomes for female and male surgeons.
"We don't know the mechanism that underlies better outcomes for patients treated by female surgeons, although it might be related to delivery of care that is more congruent with guidelines, more patient centred, and involves superior communication."
Although around 58 per cent of medical students are now women, just 11 per cent of surgeons in Britain are female.
Previous studies have shown that female medical students are better at basic surgical skills and gain higher scores on theoretical surgical knowledge tests. But the new study is the first time the difference has been observed in patient outcomes.
However the Royal College of Surgeons said although the study confirmed the 'safety, skill and expertise' of female surgeons, patients should not seek to choose a surgeon the basis of sex.
Derek Alderson president of the RCS said: "Surgery is a specialty that continues to struggle with unconscious bias among patients and health professionals, and gender inequality persists.
"This study helps to combat these lingering biases by confirming the safety,skill, and expertise of women surgeons relative to their male colleagues.
"However with so many critical factors to consider, trying to find out why there is a very small difference in short term clinical outcomes between male and female surgeons is unlikely to prove worthwhile.
"Nor are we convinced that the sex of the surgeon will emerge as an important determinant of a good outcome for patients having surgery."
The research was published in the British Medical Journal (BMJ)