Valerie Cadogan was cycling with her husband when she struck the 25cm (10in) wide, 11cm (4in) pothole and hit her head, Newport Coroner's Court heard.
Council workers were called to the area within hours to fill in the potholes in April this year and make the area safe.
Coroner David Bowen said the effects of the impact may have been lessened had Mrs Cadogan been wearing a helmet.
Mrs Cadogan was airlifted to Bristol's Frenchay Hospital after the incident but never regained consciousness. She died the following day.
The Newport Coroner's Court hearing was told Monmouthshire council immediately filled the pothole on St Mary's Road.
Mark Watkins, of the local authority's highways department, said the road is inspected annually and they had had no reports of defects there following an inspection in June 2012.
A 72-year-old cyclist died after she fell from her bike after hitting a pothole in Monmouth, an inquest heard.