The 28-year-old signed only last week for an eight game stint in the T20 Blast county competition.
The 28-year-old -- Bangladesh's highest international run scorer with more than 10,000 to his name in all forms of the game -- signed only last week for an eight game stint in the T20 Blast county competition.
Tamim appeared in Sunday's seven-wicket loss to Kent but on Tuesday Essex released a statement saying his stay was over.
"Essex County Cricket Club can confirm that overseas player Tamim Iqbal has left the club with immediate effect due to personal reasons," the statement read.
"We wish him all the best, and it would be appreciated if Tamim's privacy is respected during this time."
Tamim starred with the bat for Bangladesh in the recent Champions Trophy scoring a splendid century against England, falling five short of another century against Australia and hitting 70 in the semi-final against India.