Born to merchant father Dimitrije and housewife mother Sofija, young Blagoje grew up on the outskirts of Belgrade in 7 Đakovačka Street.
Blagoje Marjanović was one of the best footballforward in the Kingdom of Yugoslavia. He played for BSK (1926-39), with whom he won four league titles (1931st, 1933rd, 1935th, 1936) and three times was the best league goal scorer (1930th, 1935th, 1937). For the national team debut on 28 June 1926 in a friendly match against Czechoslovakia (2-6) in Zagreb. For the first time in the list of shooters entered on May 15, 1927 against Bulgaria in Sofia when in the last five minutes scoring only two goals in the match. During his career, he scored 36 goals in 57 games for national team (unbroken record, until Bobek came, and scored 38 goals in 63 games, although Marjanović has better scoring ratio at 0,63 goals per game), and 575 goals in 14 seasons for his club BSK. He participated in the 1928 Olympic Games in Amsterdam and the first FIFA World Cup 1930 in Uruguay. He has won bronze medal in FIFA World Cup 1930 in Uruguay. He scored one goal in that tournament in the game versus Bolivia. After returning from 1930 World Cup, this excellent striker became (alongside his teammate Tirnanić), first professional footballer in Yugoslavia (although he had a little bit higher salary then Tirnanić). For his services at BSK Marjanović was paid YUS1,800 per month. The exchange rate of dinar against US dollar in December 1930 was $1 = YUS56.39 meaning that his monthly salary was $32 (about $446 in 2014 dollar).He and Tirnanić formed one of the greatest right side partnership in Yugoslavian football history. Although, during the match he understood with Tirnanić very well, he had almost the same understanding with other teammates, from his club and from national team. Marjanović was highly intelligent player, and he was able to realize, how every of his teammates plays. During the game it always seemed that he knew what to do with or without a ball (especially during goalscoring situations in opponent penalty box, when he was highly unpredictable and very clever). He was very accurate shooter, but with average shot power. Moša could score from almost every position (he scored quite a few goals with his back-heel, chests and sometimes even stomach) and he didn't care if the ball came low or high, because he was, also, very good in air game. His main specialty was volley shot. Besides that, he was also one of the best free-kick takers in Yugoslavia. He scored a few times hat-trick for national team, but probably most memorable was against Brazil in 1934, in friendly game in Belgrade (the score was 8:4 for Yugoslavia). Many football experts of that time showed great appreciation for "Moša's" skills, including Hugo Meisl (creator and coach of the Austrian "Wunderteam") who claimed that with Marjanović in the attacking line "Wunderteam" would be perfect.
Marjanovic has enjoyed great fame and was a national superstar but also and a playboy, up to the moment when his club played against Hajduk, in Split. There is on the eve a match met an Dalmatian girl which supports Hajduk. They were married in 1938 with great interest of the public and journals. The last match for the national team played on April 3, 1938 against Poland in a World Cup qualifier. Then Marjanović scored the only goal of the match. During WW II he was captured. He was in a prison camp Fürstenberg, Germany. In addition to all adversity, sometimes they are organized and football matches between "war prisoners" against the "guardians". When the war ended he returned to Yugoslavia and became a player of Dinamo Pančevo (1945-48). His career ended in Proleter from Osijek (1949). During a coaching career, first led Proleter Osijek, then OFK Beograd, with which 1953 won the national cup. He was later coach in Italian league (one year in AC Torino and one year in Calcio Catania). He returned to Yugoslavia and became a coach of FK Pobeda Prilep. After an match in 1961, Moša suffered a stroke. He never came back the power of speech, the right side of his body was taken away. He died in 1984.