Pitäjänmäki has been inhabited since the Stone Age. Archeological excavations behind the playground on Nuolitie have uncovered numerous comb ceramic artefacts. The original route to Turku passed through Pitäjänmäki already in the 1500s. The history of Tali Manor dates back to the 1600s. In the 1930s a golf course was built on the grounds of the manor along with allotment gardens, a sports park and the city plant nursery.
The first privately owned company in Pitäjänmäki was the Kröckel brewery, which operated next to the Mätäjoki rapids already in the mid-1800s. The railway line was built in the early 1900s and attracted more industry and residents to the area. The Strömberg factories were founded in what was then part of the rural municipality of Helsinki in 1911. Pitäjänmäki, or “Pitsku” as it is familiarly known, became a city district in 1946.
The first town plans were made for the southern and northern parts of the industrial area, reflecting the importance of business development to the City of Helsinki. Initially the residential areas consisted mostly of small houses; the Marttila neighbourhood was developed right after the Second World War. Pajamäki was developed in the 1960s and the apartment buildings in Reimarla in the 1970s.
New residential housing was developed in the 1990s in the Strömberg, Talinlehto and Uddeholm industrial areas alongside the renovated Strömberg Park. Today Pitäjänmäki is home to around 10,000 residents and 20,000 workplaces. Major employers in the area include the Halva confectionery factory, the Teknos-Winter paint factory and the Valio juice factory. Piimäki is also home to the biggest IT cluster in Finland.
Uusin asutus nousi Pitäjänmäen teollisuusalueelle 1990-luvun aikana, kun kaavoitettiin ns. Strömbergin asuntoalue, Talinlehdon asuntoalue ja Uddeholmin kulman teollisuustonteista asumiseen muutettu kerrostalokortteli Strömbergin kunnostetun puiston äärelle. Tällä hetkellä Pitäjänmäessä asuu noin 10000 asukasta ja 20000 työpaikkaa. Yrityksistä mainittakoon Halvan makeistehdas, Teknos-Winterin maalitehdas ja Valion mehutehdas. Piimäessä on Suomen suurin IT-keskittymä.