Chandra Bahadur Dangi is 56cm tall and weighs 12kg, he told a media conference broadcast by Nepali state television.
"We intend to travel to Mr Dangi's village to officially measure him and are currently making provisions for medical professionals to assist us in the verification," Guinness World Records editor-in-chief Craig Glenday said by email.
State-run Nepal Television broadcast images yesterday of Mr Dangi jumping off a park bench and taking a short walk in front of journalists.
Members of his family were quoted by local media as saying Mr Dangi was in excellent health and had never taken medicine or been to hospital.
"We cannot confirm Mr Dangi's height until formal measurements have been taken and verified by Guinness World Records officials but we hope to undertake the verification in the next few weeks," said Mr Glenday, who is to make the journey to impoverished Dang district, which borders India.
Mr Dangi has already become something of local celebrity in southern Nepal, appearing at community events and opening religious festivals.
The record is held by Filipino Junrey Balawing, who measures 59.93cm and took the title last year from another Nepali, Khagendra Thapa Magar, who was measured in 2010 at 67cm.
Mr Magar's stint as the world's shortest man saw him travel to more than a dozen countries and make television appearances in Europe and the United States.
He was also the official face of Nepal's tourism campaign, which featured him as the smallest man in a country that is home to the world's highest peak, Mount Everest.