Syngenta posted profits of $1.8 billion, while market-watchers had predicted a figure of $1.7 billion.
Revenues for the group, which is based in Basel in northern Switzerland, hit $14.2 billion, up seven percent on the 2011 results, due to an increase in volumes and price rises.
Syngenta said in a statement that unfavourable weather conditions in 2012 had pushed up farm produce prices, leading more growers to use its products to protect their crops.
North America, for example, faced one of its worst droughts since the 1950s, leading to pressure on the market for crops such as maize.
Sales in Syngenta's crop protection division — its main revenue-driver — rose by seven percent to $10.3 billion.
The group's seeds division, meanwhile, saw a 14-percent increase to $3.2 billion.
Syngenta, the top player on the global agrichemical market, said sales jumped by 28 percent in North America and by 18 percent in Latin America in the fourth quarter.
The group is eyeing emerging markets as a new source of growth.
It said that it was planning to invest $77 million in its Brazilian production facilities, in an effort to raise output there fourfold.
Brazil is a major player on the international maize market, and Syngenta has predicted that the country's output of the crop will double by 2020.