Four funds holding £1.75bn of assets managed by Aberdeen Standard Investments have made Tilney's annual Spot the Dog list of underperfoming funds.
No other asset manager has four funds on the list.
The funds are the Aberdeen UK Equity Income fund, the £212m Aberdeen UK Equity fund, the £54m Aberdeen European Smaller Companies fund and the Aberdeen Asia Pacific Equity fund.
Funds are placed on the list if they have failed to beat their relevant benchmark for three consecutive 12 month periods.
A spokesman for Tilney said: "In recent years Aberdeen Asset Management was one of the most prominent groups in our doghouse and following its merger with Standard Life last year, the combined business has £1.75bn of assets across four funds, all of which came from the Aberdeen side.
"The trend has improved from a low point two years ago, when 11 Aberdeen funds were featured, and as the integration of the Aberdeen and Standard Life businesses progresses we expect a rationalisation of the combined fund range which will provide an opportunity for the group to put its dog days behind it."
A spokesman for Aberdeen Standard Investments has been asked to comment on being named 'Top Dog' in Tilney's list.
Fidelity was the next worst performing fund group, with two funds on the list, including the Fidelity American fund, which changed manager in summer 2017.
St James Place was a major improver, with just one fund on the list, compared to three when the list was compiled last year.
The fund in question is the St James Place Asia Pacific fund, which changed manager from Aberdeen to First State in 2016.
Jason Hollands, managing director for communications at Tilney, said: "In the last five years the number of dog funds has been as high as 60 and only two years ago there was as much as £18bn tied up in such investments.
"The drop in the number of both dog funds and the amount of investor money in these is very welcome.
"Only time will tell whether this is a temporary blip or a sign that the investment industry has got its house in order by replacing underachieving managers or merging away seriously failing funds.
"For investors, spotting a seriously underperforming fund has become incredibly difficult in recent years.
"Soaring stock markets mean that even funds that have lagged far behind have still made strong positive returns.
"The median return across all dog funds listed in the latest report during 2017 was 10.8 per cent and only one fund actually failed to make investors any money and that was flat rather than a loss maker.
"In rocketing Asian and Emerging Markets, you could have even experienced returns of over 20 per cent last year in dog funds.