Tauranga urologist Liam Wilson has been performing vasectomies for nine years but refuses to operate on men who have any doubts about having the snip.
Doubts were often revealed during a consultation the men attended before booking an appointment to have the operation under a local anesthetic, Dr Wilson said.
Some men returned with their mind at rest while others simply failed to show up for their appointment, he said.
At Bay Urology about 150 vasectomies are conducted on "Vasectomy Friday", aimed at giving patients a chance to recover over the weekend before returning to work on Monday.
Dr Wilson said about half of men were happy to be there, the other half said: "My wife made this appointment for me."