As a civil servant trainee, Fischer completed the preparatory service for the higher non-technical service in the tax administration. After successfully passing the examination, he began working at the Stuttgart II tax office in 1962. In 1964/1965, he was employed at the Stuttgart Regional Finance Office, then at the Stuttgart Corporate Tax Office, before moving to the Baden-Württemberg Ministry of Finance in 1969. On May 13, 1982, Fischer was elected by the city council as district leader of the Bad Cannstatt district.
During his 24-year tenure as district leader, important projects were realized or initiated, such as the development of the Brenzstrasse/Obere Waiblinger Strasse conversion area and the new Burgholzhof district. This was associated with the establishment of a functioning public and social infrastructure and the integration of the new citizens. Fischer lobbied for the new buildings of the Cannstatt mineral baths and the district office on the market square. In 1994, Fischer co-founded the Cannstatter Volksfestverein (Cannstatt Folk Festival Association), which organizes the annual Cannstatter Volksfest pageant, and served on its board until 2016. Hans-Peter Fischer retired in 2006.