The research house added the BT Wholesale Midcap Fund, Hyperion Small Growth Companies Fund and Realindex RAFI Australian Small Companies - Class A Fund.
All three funds received a recommended rating.
"Zenith now has three funds available in the mid-cap segment and believes that these funds may be useful for clients seeking access to funds with a more subdued risk/return profile than small-cap funds," Zenith senior investment analyst James Tsinidis said.
Only two of the 12 funds received a highly recommended stamp.
They were the Ausbil - Australian Emerging Leaders Fund and Eley Griffiths Group Small Companies Fund.