The home side made a slightly nervous start, but once they took the lead midway through the opening period, the confidence lifted and there was only one winner after that.
Tommy Miller missed a good chance after a one-two with Shefki Kuqi, firing straight at Paul Gerrard, before the Forest keeper rushed out to block a Darren Bent chip from a Kuqi flick.
Town went ahead in the 27th minute when Jim Magilton curled in a corner and Richard Naylor lost his marker to dive forward and head in from a couple of yards.
It could have been two on the half-hour when David Unsworth miscued a left-wing cross which went over Gerrard's head, but rebounded off the far post, with Bent hitting the loose ball into the side-netting.
Andy Melville cleared well as Kuqi closed in on a Matt Richards header across goal, before Miller twice tried his luck with volleys - one well over, the other cleared off the line by Alan Rogers.
A second goal was coming and it arrived on 35 minutes when Richards crossed to the far post, Kuqi headed it down and after Gerrard palmed it away, Ian Westlake chested down the loose ball and poked home his first goal since November 2.
Bent could have added a third before the break, expertly taking a long ball in his stride and rounding Gerrard, but Melville and Chris Doig got back on the line, with the latter blocking the shot.
Forest needed a good start to the second half, but they didn't get it as Ipswich made it 3-0 on 51 minutes, Bent beating Melville to the byline and pulling the ball back for Miller to fire home.
A brief Forest flurry saw Gareth Taylor shoot wide from a Scott Dobie flick-on, before Dobie headed over from an Alan Rogers cross.
Kelvin Davis saved a Kris Commons volley and then dived to keep out David Friio's touch from a fine John Curtis cross, but Ipswich then hit the visitors with three goals in seven minutes.
On 64 minutes, sub Darren Currie played in Bent who was hauled down by Wes Morgan. Morgan was booked before Miller maintained his 100 per cent career penalty record, sending Gerrard the wrong way.
Town's top scorer Kuqi got his 16th of the season three minutes later when Bent's driven low cross was palmed away by Gerrard, Fabian Wilnis headed the rebound against the bar and Kuqi was in the right place to tap in.
The scoring was completed on 71 minutes when Bent was rewarded for an all-action display, swapping passes with Westlake before firing home a deflected shot from the edge of the box.
Forest had no answer, despite several formation changes and manager Gary Megson sending on all three subs before an hour had gone, and he will hope they can swiftly put this result behind them.
Ipswich meanwhile will hope to move on from the platform of this resounding win and maintain the pressure on the leading two, Wigan and Sunderland.