The firm said in a trading statement today that assets under management stood at Â£71.4 billion compared with Â£74.4 billion at the end of March.
It attributed the decline to the ten per cent drop in value of the dollar against sterling, in addition to assets being withdrawn from the recently-acquired UK arm of Deutsche Asset Management (DeAM).
"The biggest single part (of the fall) was the US dollar ... Following the Deutsche acquisition, we've got a bigger portion of US assets," group finance director Bill Rattray told Reuters.
The firm also said it would pay around Â£25 million for Deutsche's equity and multi-asset business, which it took on last year.
Katrina Preston, an analyst at Bridgewell, said Aberdeen had performed well during touch stock market conditions over the past few months.
"Aberdeen appears to have emerged unscathed from the recent turbulence across global ... equity market," she said.
"The company remains one of our preferred plays in the fund management sector. The shares' de-rating against the peer group since May looks increasingly misplaced and we remain strong buyers."