The Japanese carmaker saw European sales drop 3.9% during the last quarter.
Nissan offset the drop by selling more cars to the US and China, pushing quarterly operating profit up 11%.
Operating profit in the first quarter totalled 206.26bn yen (£1.3bn), Nissan said.
Net profit, however, dropped 14% to 105.7bn yen (£541m) in the three-month period, mainly due to a change in accounting rules.
While Europe is proving to be a weak spot, Nissan - 44%-owned by Renault and Japan's second-biggest carmaker - has seen sales improve elsewhere.
During the first three months of its financial year, total sales rose by 13% to 2.145 trillion yen (£11bn).
In the US and China, growth topped 18%, while within Japan sales climbed by almost 19%.