In the verdict of the Serbian Supreme Court in Belgrade on April 19, 1967 on the Mihajlov case and his initiative to establish an independent cultural magazine called Slobodni glas, the Court sentenced him to three and a half years in prison, to be served in Srijemska Mitrovica. After the first-instance verdict of the Belgrade court, Mihajlov and his attorneys Kovačević and Glowatzky appealed without success. Despite this complaint, he was sentenced under Article 118 of the Criminal Code for engaging in hostile propaganda. They had attempted to defend him by asserting that the proposal to establish a Christian-socialist party and democratic socialism was a form of benign academic debate which was not anti-constitutional act in any way.

The Serbian Supreme Court in Belgrade regarded the defence’s reasoning as unfounded, accusing Mihajlov of the hostile action “against the social and political organization” of the Socialist Federal Republic of Yugoslavia. In addition to these initiatives, the Supreme Court charged him for frequent communications with “émigré and reactionary organizations” abroad and for his correspondence with the press of Western capitalist countries (Mihajlo Mihajlov Papers, box 3).