Full-year underlying replacement cost profit at the oil company fell to $17.6bn (£11.2bn), compared to $21.7bn over 2011.
Profits for the fourth quarter came in above expectations though, at $4bn compared to $5bn over the same period in 2011, helped by record earnings from its downstream business.
The results come just days after a US court approved a $4bn settlement for criminal penalties relating to the oil disaster, which killed 11 workers and spewed oil into the Gulf of Mexico for three months.
BP added that it took a $4.1bn additional charge in the fourth quarter, primarily reflecting its criminal settlement agreement with the US Department of Justice.
"We have moved past many milestones in 2012, repositioning BP through divestments and bringing on new projects," said BP chief executive Bob Dudley this morning.
"Moving through 2013 we will deliver further operational milestones and remain on track for delivery of our ten-point strategic plan, including our target for operating cash flow growth, by 2014."
The oil behemoth added that the sale of its interest in TNK-BP to Rosneft is due to complete in the first half of this year.
BP expects four new major upstream projects to begin production by the end of 2013 – Angola LNG, North Rankin 2 in Australia, Na Kika 3 in the Gulf of Mexico, and the Chirag Oil project in Azerbaijan.