African Underground Mining Services (AUMS), a joint venture between Ausdrill and soon-to-be Ausdrill-owned Barminco, won the work in conjunction with Ghanaian mining contractor Rocksure International under a 70:30 alliance.
The $450-500 million Obuasi project should pour first gold next year and ramp up to 350,000-450,000 ounces of gold per annum at all-in sustaining costs of $750-850 an ounce.
Under the contract, the JV will provide a full suite of underground mining services at Obuasi, with major capital equipment supplied by AngloGold Ashanti.
Works are expected to begin in the first quarter of 2019 and employ around 550 people over the five-year term.
The workforce will be dominantly Ghanaian with some expatriates providing training and development and specialist skills.
AUMS has been working in Ghana for the past seven years and has five active projects.
Last week, shareholders of Barminco approved an acquisition by Ausdrill, which will see it take full ownership of AUMS.
In what has been a successful few days for the combined entity, it was announced on Wednesday that Barminco had won a four-year, A$240 million contract extension at Independence Group's Nova nickel-copper mine in Western Australia.
Ausdrill shares closed 1.8% higher at $1.68, close to their 52-week low of $1.538.