The West Brom forward came from the bench to score the only goal and give Giovanni Trapattoni a headache over who will partner Robbie Keane in Poland-Ukraine
Half-time substitute Aiden McGeady provided the moments of genuine spark and quality and Long's header in the 77th minute ensured another win for Giovanni Trapattoni's side ahead of this summer's European Championship.
Ireland began with Sunderland starlet James McClean making his full debut and Keiren Westwood deputising for Shay Given in goal, whilst Paul McShane also started, at right back in the absence of John O'Shea, despite not being a part of Trapattoni's squad for Euro 2012.
Bosnia failed to qualify for the championships in Poland and Ukraine this summer, having been beaten in the play-offs by Portugal, but they settled the quicker of the two sides at Lansdowne Road and created the first meaningful opportunity of the match in only the third minute.
Clever play down the right between Edin Dzeko and the Roma midfielder Miralem Pjanic, freed the Manchester City striker who crossed for Vedad Ibisevic, and the Stuttgart man was mere inches away from turning the ball past Westwood.
Minutes later and the two sides exchanged rather hopeful penalty appeals following an injury scare for Robbie Keane, who took a knee to the midriff from Boris Pandza; first, Ireland's Glenn Whelan burst through on goal and appeared to be brought down by his Stoke team-mate Asmir Begovic, before Zvjezdan Misimovic, the Dinamo Moscow playmaker and Bosnia captain, saw his shaped effort blocked by the body of McShane. However, on both occasions the referee remained unmoved.
Ahead of this summer's tournament, much has been made of the hype surrounding Sunderland winger McClean, and starting on the left side of Trapattoni's four-man midfield, his forceful running created Ireland's first sight of goal. The former Derry City winger cut inside both Mudjza and Pandza before Everton midfielder Darron Gibson, looking to stake his own claim for a starting spot at Euro 2012, skewed his shot wide.
Ireland were gradually growing into the game, and a good spell of patient possession led to a chance for Damien Duff in the 32nd minute, who, cutting in from the right touchline, drilled a daisycutter of a shot just wide of Begovic's left-hand post.
In the 39th minute, Westwood made a comfortable save from a 30-yard strike from Pjanic before McClean forced a decent save from Begovic at his right-hand post with a low, angled drive.
On the stroke of half-time Ireland were unfortunate not to take the lead, after excellent combination play from Duff and Keane, two stalwarts of their last major international tournament, the 2002 World Cup in Japan-South Korea.
A clever pass from Whelan split the Bosnia defence and found the evasive run of Keane, who, with his back to goal 12 yards out, drew two defenders towards him before slipping in Duff with a clever flick, but Begovic was quick off his line to thwart the danger at the expense of a corner.
At half-time Trapattoni shuffled his midfield, with West Brom midfielder Keith Andrews and Spartak Moscow's skilful winger McGeady replacing Duff and Whelan respectively, and McGeady made an immediate impact.
A flighted free-kick from Stephen Ward found his Wolves club-mate Kevin Doyle at the edge of the box, and his header on was volleyed off the post by the recently-arrived McGeady.
Bosnia made a couple of changes of their own at half-time, and one of them, Damir Vrancic, suffered the ignominy of being the first player into the referee's notebook, shown a yellow card for bringing down Richard Dunne in the 50th minute.
The second half was as sluggish as the first, with both sides seemingly happy to play the game at half pace, but one bright spark for the away side throughout was Pjanic and the talented 22-year-old forced a smart save from Westwood with a dipping free-kick in the 58th minute.
Five minutes later Trapattoni made a double change up front, replacing strike duo Doyle and Keane, with Shane Long and Stoke's workaholic forward Jon Walters. Both had an impact.
Firstly, Walters missed a glorious chance in the 73rd minute, heading against the crossbar from six yards after a splendid right wing cross from McGeady.
Four minutes later and Ireland took the lead courtesy of Long, who showed Walters how to score with a header from six yards, beating Begovic at the back post after another wonderful pin-point cross from McGeady.
Sixty seconds later and Walters came close to doubling Ireland's lead, but, having been played clean through, he could only hit his shot against the on-rushing Begovic.
Ireland finished the match much the stronger, with McGeady at the heart of everything, and the former Celtic man almost teed up Long for a second in injury time.
Picking the ball up in an inside left position, McGeady played a one-two with Walters, before chipping the ball across the box for Long, whose goalbound header was brilliantly saved by Begovic. On the follow-up, Keith Andrews headed the rebound over the crossbar.