Justice Ghulam Mustafa Mengal was born on the 25th of December 1952, at Quetta (Balochistan).
Justice Ghulam Mustafa Mengal did his matriculation in 1971 and F.A. in January 1974, from the University of Balochistan. He completed his B.A. in March 1976, and L.L.B. from the University of Law College, Quetta (University of Balochistan).
Justice Ghulam Mustafa Mengal entered the legal profession on the 15th of November 1988, and joined the Chamber of Muhammad Muqeem Ansari, a leading advocate of Balochistan.
He enrolled as an advocate of the High Court on the 14th of February 1991 and of the Supreme Court of Pakistan on the 13th of September 2008.
On the 18th of November 1999, Justice Ghulam Mustafa Mengal was appointed as Assistant Advocate General, Balochistan, and on the 24th of September 2002, he was appointed as Additional Advocate General and served in this position till the 23rd of September, 2004.
During his career with the Bar he was elected as the Secretary of the Library of the Balochistan Bar Association, and in 2006 as the Vice President of the Balochistan High Court Bar Association. On the 9th of July, 2009, Justice Ghulam Mustafa Mengal was appointed as Chairperson, of the Environmental Protection Tribunal, Balochistan and as Senate Member of Sardar Bahadur Khan Women University on the 17th of September, 2012.
Justice Ghulam Mustafa Mengal was elevated as Additional Judge, High Court of Balochistan on the 7th of September 2009, and confirmed as Judge of the High Court of Balochistan on the 11th of May 2011.
Justice Ghulam Mustafa Mengal was appointed as Tribunal of Inquiry twice for the purpose of making inquiries into the tragic incidents of killings/firings, which took place on the 15th of January 2010, at City Khuzdar and on the 3rd of March 2010, at Balochistan University of Engineering & Technology, Khuzdar, respectively.
Justice Ghulam Mustafa Mengal attended the Judicial Conferences held at Islamabad in 2010, 2011 and 2012, and the Regional Seminar at Lahore in September 2011, organized by the Supreme Court Bar Association. He also attended the South Asia Conference on Environmental Justice at Bhurban, Muree in March 2012.
Justice Ghulam Mustafa Mengal took oath as Chief Justice of the High Court of Balochistan on September 5, 2014, and retired as Chief Justice of the High Court of Balochistan on December 24, 2014.