UBS said in a statement that net profit leapt 79 percent to 1.3 billion Swiss francs ($1.3 billion, 1.1 billion euros) in the first quarter.
That was better than expected by analysts interviewed by the Swiss agency AWP, who had forecast profits of around 916 million Swiss francs.
"Despite facing a variety of market conditions and client activity levels, all business divisions and regions contributed to the improvement in performance," UBS said in a statement.
Looking ahead, UBS said that "while the global recovery is likely to continue, macroeconomic uncertainty, geopolitical tensions and divisive politics pose risks that may affect client sentiment and transaction volumes."
Low and negative interest rates, particularly in Switzerland and the eurozone, "continue to present headwinds to net interest margins," it said.
"These may be partially offset by the effect of higher US dollar interest rates and a further normalization of monetary policy."
Implementing Switzerland's new bank capital standards and the proposed further changes to the international regulatory framework for banks would result in increased capital requirements, interest and operating costs, it warned.
But it added: "UBS is well positioned to mitigate these challenges and benefit from further improvements in market conditions."