Operating profits rose from £21.09m to £27.09m. However, the company said, like-for-like sales had slowed in the second half.
The results came in below ING Barings Charterhouse Securities' expectations. It had forecast pre-tax profits of £21.6m.
The company opened 42 pubs during the first half. These included its first two houses in Northern Ireland. It has opened another seven new pubs in the second half and has licensing permission for another 80. Of these, 41 are under construction.
JD Wetherspoon reported that like-for-like sales had slipped to 3.1% in February, bringing the 470-strong national pub chain closer to the industry norm. It had enjoyed 6.5% growth in the half-year to the end of January. This included a 10% rise during the Christmas period.
Jim Clarke, Wetherspoon's finance director, said March like-for-likes had improved with the help of marketing initiatives.