The firm saw its funds reach £55.8bn by the end of March, made up of £45.5bn in the investment management business and £10.3bn in the Rathbone funds business.
Total net inflows were £700m, representing an annualised net growth rate of 5.1 per cent.
Gross flows in investment management hit £1.2bn, up from £1bn in the same period last year, and Rathbone funds recorded £1.1bn of gross inflows, with net inflows of £500m.
The group’s investment management fees were up 40 per cent compared with the same period in 2020, attributed to increased funds under management and the impact of more fee-based income from the Speirs & Jeffrey acquisition in 2018.
Paul Stockton, chief executive of Rathbones, said: "We continue to deliver on our strategy, progressing our responsible investing agenda with the addition of four new Rathbone Greenbank multi-asset portfolios in the first quarter.
"As markets begin to look beyond the pandemic, we will pursue our plans to strengthen services to clients and advisers and take advantage of future growth opportunities."
Following the early retirement of chairman Mike Nicholls, Clive Bannister will succeed interim chairman Jim Pettigew at the company's AGM today.
Colin Clark will succeed Jim Pettigew as senior independent director, subject to regulatory approval.