The engineering and construction was given the honour at the Moray Chamber of Commerce Awards.
The company, which will be celebrating its 20th year in business next year, was recognised for its continued commitment to employing apprentices and its great turnover, which has increased year on year for at least the last three years.
Attending the event on behalf of the company was general manager Graham Alexander and business development representative Lee Binks.
Graham, who has worked at AJ engineering for five years, said: "We are absolutely thrilled to have been chosen for the Moray Chamber of Commerce's Small & Medium Enterprise of the Year 2018 award. It is a credit to the hard work of a dedicated workforce.
"We truly had no idea that we had been successful and were looking forward to a great awards lunch at the Mosset Tavern, purely as attendees rather than as award winners."
He added: "Moray has such a wide range of great businesses representing a variety of sectors. It makes this award all the more pleasing to be recognised amongst such fantastic competition.
"All businesses, of all sizes, face challenges. It is those that find the opportunities within those challenges that succeed. Liz Cameron OBE, Chief Executive of Scottish Chambers of Commerce gave the keynote speech at the awards event which I found very inspiring. Moray may have a relatively small footprint, but it makes a big impression.
"With the support of Moray Chamber of Commerce, many Moray businesses have grown to be international brands and I've no doubt there are many, many more great organisations yet to emerge from Moray."
Last month, AJ Engineering joined forces with Forres-based form Rennie Fabrication to create an engineering powerhouse giving the company scope to take on more varied work in a wider range of sectors.
Notable projects for the firm include a £2 million project for SSE on its Stronelairg Wind Farm near Fort Augustus, works with BAM Nuttall for a steel platform 8000 miles away on Bird Island, South Georgia in Antarctica and continued works on the Forth Road Bridge and Queensferry Crossing.
Wild Blossom, a Forres-based floristry firm, run by Graham's wife Bev Alexander and Caroline Byrne was also recognised.
They shared the award for Most Promising Enterprise with Falcon Building Supplies whilst Speyside Cooperage Limited won the Moray Export Award.
