A right-arm fast bowler, Shafiul Islam had an impressive debut in 2007 for the Rajshahi Division as he bowled a terrific spell, taking five wickets. The right-arm pacer showed promising signs with the new ball and caught the selectors' eye. An untimely injury to senior bowler Mashrafe Mortaza earned him a national call-up.

Shafiul was included in the ODI squad for the 2010 home Tri-series against India and Sri Lanka. He made his ODI debut against Sri Lanka, while his Test debut came against India in the same series. Later, in the 2011 ICC Cricket World Cup, Shafiul impressed with his lower-order batting that helped Bangladesh clinch a thriller over England.