Broad went on to have an equally successful ODI series against New Zealand. Although England fell to a three-one defeat, Broad was the leading wicket taker and held the highest batting average, 52, in the England team. During the tour of New Zealand in 2008, Broad, along with Alastair Cook and James Anderson, posed naked for the Cosmopolitan paper with just a cricket bat for cover. England won the first Test against New Zealand by 121 runs, with Broad taking figures of 3–54 to help England win the game.
In the first Test against New Zealand on home soil, Broad took three wickets in the match. England won the second match by six wickets, although Broad picked up no wickets in the match. On 6 June 2008, Broad scored his maiden Test fifty, against New Zealand at Trent Bridge, making 64 before being bowled by Chris Martin. In the first ODI against New Zealand Broad took 2–14, before taking another two wickets in the final match of the series, conceding fifty runs in the process.
He made his second Test fifty in July 2008, in the Test series against South Africa, scoring a new best of 76. In the Second Test at Headingley, Broad contributed seventeen runs in the first innings, as England was bowled out on the first day for 203. In the second innings, with the match already lost, Broad top-scored with 67 in an innings that included some impressive drives through midwicket and cover, giving further evidence of his batsmanship. After this, his Test batting average briefly rose above 40. His performances with the bat at the time led pundits to suggest that he may become a genuine all rounder, with Geoffrey Boycott comparing him to Garfield Sobers: "He's a wonderful player. There's a little bit of Sobers in him". Broad was surprisingly dropped for the following Test at Edgbaston, making way for the returning Paul Collingwood. England captain Michael Vaughan said he was left out because of his bowling, but the decision has been criticised: Collingwood was no better a bowler than Broad, and Broad's batsmanship quite encouraging. Broad duly took seven wickets for Nottinghamshire against Durham while the Test was being played.
On 26 August 2008, he recorded the first five-wicket haul in his international career with best figures of five for 23 against South Africa at his home ground in the second ODI of the series, with England winning the series 4–0 with Broad taking 8 wickets within the series at an average of 18.4 and shooting up to 4th in the ICC ODI world rankings, the highest in his career and the best by any English bowler since Andrew Flintoff in 2003.