Harmony Gold is the third largest gold mining company in South Africa, the 12th largest in the world (2009) and the 5th largest gold producer in the world. Harmony and its subsidiaries conduct underground and surface gold mining and related activities, including exploration, processing, smelting and refining. During the fiscal year ended 8 October 2004 (fiscal 2004), the company processed approximately 33.955 million tons of ore and sold 3,225,187 ounces (100,376.7 kg) of gold. It also has operations in Australia, Papua New Guinea and Canada. The company owns a number of mines including Elandskraal mine and Phakisa Mine. In South Africa, Harmony Gold holds at least nine mines, an open-pit mine, and many surface operations.[3]

The Big Bell Gold Mine was acquired by Harmony through the take over of New Hampton Goldfields Limited in April 2001 for A$54 million. Harmony closed the mine in June 2003, having found previous assessments of the grade at Big Bell over optimistic and making mining the deposits thereby unprofitable. In January 2010, the mine was sold to Aragon Resources Limited, who chose to rename the project to Murchison Bell.

Acquired through the take over of Abelle Limited in April 2003, Harmony sold on the Gidgee Gold Mine in November 2003 to Legend Mining for A$6.5 million.

The Hill 50 Gold Mine at Mount Magnet, in care and maintenance since December 2007, was acquired by Harmony in 2002 when the company took over Hill 50 Gold. Harmony sold the operation to Monarch Gold Mining in late 2007, but Monarch was unable to complete the transaction and went into administration in July 2008. After being unable to re-sell the mine, Harmony conducted a study in regards to carrying out mining at Hill 50 once more. It is currently considering the option of consolidating historic resources into one large super pit, rather than to carry out costly underground mining. Harmony expects the study to be completed in the third quarter of 2010.

The South Kalgoorlie Gold Mine became part of Harmony with the take over of Hill 50 Gold. Harmony sold the mine to Dioro Exploration NL and the later settled the purchase of the mine on 30 November 2007. Harmony received A$45 million for the operations, of which $25 million were in cash while the remainder was paid in Dioro shares.

Hidden Valley is an open-pit, gold-silver mine and processing plant in Morobe Province. The mine is approximately 210 km north-north-west of Port Moresby, and 90 km south-southwest of Lae. It is operated by Morobe Mining Joint Ventures, a 50:50 joint venture between Harmony and Newcrest Mining.

In late May to early June 2009 63 illegal miners died in a Free State, South Africa mine owned by Harmony Gold.

On Thursday 28 September at around 6pm the regional manager of Harmony Gold, Simphiwe Kubheka was shot dead at Harmony Mines in Welkom, South Africa.

In South Africa, Harmony Gold secured a license to sell a replica of the One Ring, made from gold taken from the Bloemfontein mine, the area where The Lord of the Rings author J. R. R. Tolkien was born. Their version of the ring, also inscribed with elvish script, sold in a variety of sizes in various jewellery stores throughout South Africa and directly through their website.