Shares fell 3% after the bank said pre-tax profits were 4% lower than the same period last year at $4.8bn despite a 6% increase in revenues to $13.7bn.
That was after operating expenses surged by 13% to $9.4bn.
HSBC said this increase reflected "investments to grow the business and enhance our digital capabilities".
The bank also said it was returning $2bn to investors through a share buy-back but expected this to be the only such buy-back this year.
Chief executive John Flint said: "Our global businesses performed well in the first quarter, maintaining momentum from the end of 2017."
He added the bank had been "making further headway in the UK mortgage market".
Mr Flint said in the first quarter HSBC "increased investment in retail banking and wealth management to further grow our market share in the UK and mainland China".