In an update this morning, the firm revealed funds under management at 31 March were £89.9bn, down from £90.8bn in the previous quarter, but up on 2017 (£79.84bn).
Net inflow of funds for the quarter was £2.6bn, up from £1.99bn in the first quarter of last year.
The company maintained “strong retention of client funds” at 96%.
Andrew Croft, chief executive, said: “After a record year for new business in 2017, we have maintained momentum in the first quarter of 2018.
“Gross inflows of £3.91bn in the quarter were 21% higher than the prior year, while net inflows of £2.60bn were 31% higher, reflecting the continuing excellent retention of existing client investments.
“Weaker investment markets resulted in funds under management closing at £89.91bn, marginally lower over the three months but still up strongly over the past year.
He added: “We continue to see a growing market for trusted face-to-face financial advice and believe St. James’s Place remains ideally placed to meet this need.
“This growing market, together with the strong start we have made to 2018, reinforces our confidence in our ability to achieve our stated objective of 15-20% growth in gross inflows during 2018 and beyond.”