Maierhofer's good performances during his initial loan spell at Rapid Wien secured him his first call-up to the Austrian national team in April 2008, when he was named to the country's preliminary squad for the UEFA Euro 2008 finals. However, he would not make the final cut.
On 20 August 2008, he eventually made his international debut, in a 2–2 friendly against Italy, in Nice. He scored his first international goal when he scored inside the first minute against the Faroe Islands on 5 September 2009.