Peter Mulichkowski started his architectural career studying at University of Ljubljana, studying under Edvard Ravnikar. He graduated in 1957 and just two years later, he was elected to become an assistant professor for the architecture school's Technical faculty. In the early 1960s, he traveled to the US where he spent a great deal of time studying UC Berkley, Harvard and at Frank Lloyd Wright's Arizona research compound Taliesin West.

Mulichkoski's interests were in cultivating a unique Macedonian style of modernist architecture which fused the traditional aspects of Macedonian heritage with the new trends of minimalist and streamlined design being popularized at that time. He was interested in using contemporary materials, glass, concrete, metal in such a way that he exhibited their natural color, structure and texture. In 1970, he was award his largest commission yet, the central 'Chamber of Administration' buildings for the Macedonian government in Skopje on the banks of the Vardar River. A few years later he was given another government commission to construct a large public spomenik complex in Kavadarci, commemorating the fallen fighters of the National Liberation War. In 1978 he was elected at University of Ljubljana as a full professor.

Mulichkowski continued teaching and designing buildings for many decades. Over his long career, he has won numerous awards and created a significant amount of buildings, monuments and sculptures and is considered one of the fathers of Macedonian modernism. In 1995 he won the coveted Macedonian 'Andrea Damian award' for a lifetime of achievement in architecture. In the 2000s, he wrote a series of book, "The Spirit of the Macedonian house", "Spirit of Macedonian Construction" and "The Spirit of the Macedonian capital", celebrating the uniqueness and importance of Macedonian architecture. In 2013, he fought against the Macedonian government's plans to overhaul and redesign the government buildings he created in 1970. Despite his objections, the original facades were removed and replaced with a neo-classical design in 2014. Mulichkowski currently lives in Skopje and is still designing buildings.