In the ballroom at Government House the man who said he would not serve in a cabinet that had "Nick McKim or Kim Booth or any other Green in it", Treasurer Michael Aird, appeared to have left any animosity at the door.

He shook Greens leader Mr McKim's hand and greeted Denison Greens MHA Cassy O'Connor with a kiss on the cheek.

The cabinet now includes a de facto couple in Mr McKim and Ms O'Connor and a brother and sister pair in Health Minister Michelle O'Byrne and Environment Minister David O'Byrne.

Newly elected Mr O'Byrne agreed that there can be tensions between siblings, but said he and Ms O'Byrne would leave any that may crop up at the cabinet door.

"Mum would never forgive us if we let an argument spill from the kitchen table," he said.

The ministry also includes an old face, Bryan Green, who was relegated to the back bench not long after the 2006 election.

Mr Green, who polled well in Braddon, was all smiles yesterday, pleased to make a return to cabinet.

"It's a fantastic feeling," he said.

And there was no hiding the delight of the Greens at being included in cabinet, Mr McKim as a minister and Ms O'Connor as a secretary to cabinet.

Former Tasmanian Greens leader Peg Putt was present but Bass Greens MHA Kim Booth was absent.