Bangladesh were hoping to get some inside knowledge from MacGill, who took 208 wickets in 44 Tests for Australia, before the crucial home series against Steven Smith's team beginning later this month.
MacGill was expected to join another Australian, Mark O'Neill, on the Bangladesh backroom staff for the tour by the world number four-ranked nation.
"You know that our president (Bangladesh Cricket Board president Nazmul Hassan) already cleared it that Stuart MacGill was our first choice as spin bowling coach," BCB chief executive officer Nizamuddin Chowdhury said.
"(But) for some of his personal reasons he cannot join the team at the moment," Chowdhury told reporters at a press briefing in Dhaka.
"We will now go for our second or third option. We hope within a day or two we will be able to tell something about this," he said.
Bangladesh have been without a spin bowling coach since the BCB sacked Sri Lankan Ruwan Kalpage, who failed to report for duty following a deadly Islamist extremist attack at a posh Dhaka cafe in July last year.
Bangladesh, who offered MacGill a short-term deal for three months, were looking to build on a year in which they recorded their maiden Test wins over England and Sri Lanka before reaching the Champions Trophy semi-final in June.
Australia are due to arrive in the Bangladeshi capital on Friday for their first Test series in the South Asian nation since 2006.
The first Test against Australia is at Dhaka's Sher-e-Bangla National Stadium from August 27. The second starts in Chittagong on September 4.
Australia were to play two Tests in Bangladesh in October 2015 but the tour was cancelled after a wave of attacks by Islamist extremists in the Muslim-majority nation.
First Published: August 17, 2017, 5:29 PM IST