Sheikh began his public service career as an economist with the Economic Council of Canada from 1972 to 1976.
After a brief stint with the National Energy Board between 1976 and 1978, he joined the Department of Finance and rose to the rank of Senior Assistant Deputy Minister in 2000.
On July 21, 2010, Sheikh resigned from that post, following a controversy resulting from the Conservative government's decision to no longer require mandatory completion of the Canada 2011 Census long form.
[5] Following his resignation, in a public letter, Sheikh expressed his disapproval of the government's decision, writing: I want to take this opportunity to comment on a technical statistical issue which has become the subject of media discussion.
Media reports claiming Clement had said that this change was made on the advice of Statistics Canada were later shown to be incorrect, although this did not change Mr. Sheikh's decision to resign, as he felt the mere perception StatsCan supported the decision was cause for resignation.