He was a statistics graduate from the Karl Marx Higher Institute of Economics and held a number of positions in the Ministry of Communications and Information during communist rule.

He was elected Mayor of Sofia in 1995 and served in this position, being re-elected twice - in 1999 and 2003, until 2005 when he resigned to become a parliamentary deputy.

He was appointed as caretaker Prime Minister by President Petar Stoyanov in 1997 until snap election and such time as Ivan Kostov could form a government.

On January 1, 2007 he joined the European Parliament as one of Bulgaria's interim members until the elections in May of the same year.

In June 2008 Sofiyanski drew criticism from human rights advocates for his homophobic remarks following Bulgaria's first gay pride parade.