The Swansea-based firm shrugged off a declining market to lift turnover 75% to £136m ending a year of rapid expansion.
The company has carried out several high-profile projects over the course of the past 12 months including ongoing works in support of iron ore mining in Sierra Leone.
In January, Dawnus started a £12m infrastructure contract in Senegal.
The company was also contracted to construct three new buildings at Tata’s Port Talbot steelworks which were designed to be among the most environmentally friendly in the UK.
Dwr Cymru Welsh Water has recently announced that they have selected Dawnus as a Tier 1 Framework Contractor across all the Welsh regions.
The work will involve the construction and maintenance of water and waste water treatment works, tanks, pumping stations and other Dwr Cymru Welsh Water assets.
In the year ahead, the group said it would continue to focus on securing large civil engineering contracts, employing its own labour force and plant in order to maximise quality and delivery and minimise costs.
Dawnus now employs over 650 people in the UK with another 1,100 working on projects overseas, nearly three times the number a year ago.
The contractor is also in the process of building a new extension to its head office in Swansea to accommodate its growing staff numbers.
It will open this month and will almost double the size of the facility.
Finance Director Tim Lowe said: “The results reflect the great strides made by the company in the last 12 months.
“We have increased our geographical coverage in both the UK and Africa and look forward to building on these results in 2012.”
Dawnus currently employs over 650 people in the UK with another 1,100 working on projects overseas.