The origins of Piaseczno date back to the 13th century. The town's location  on the main route from Warsaw to Czersk  contributed to its development. In 1429, Duke Janusz I granted the Chełmno Law to the settlement and endowed it with the status of a town. In the first half of the 15th century, a local parish was established.It became a local centre of trade and service. Its further development was triggered by a privilege granted by Duchess Anna Jagielonka in 1513, which allowed the town to hold fairs every year and markets every week. The townsmen dealt mainly with trade and farming, and among the craftsmen, the shoemakers from Piaseczno were held in high esteem.

After the incorporation of Mazowsze into the Crown of the Kingdom in Poland in 1537, Piaseczno became a royal town and seat of the non-judicial starostwo. It was seriously damaged during the Polish-Swedish War, the  (1655-1660) contributed to its downfall. The number of inhabitants decreased to around 350. Pduring the Great Northern War (1700 – 1721). After it had been rebuilt, a fire destroyed it again in 1730. The town hall and archives were burnt down. The fact that the position of starosta was taken over by Aleksander Sułkowski, a favourite of king Augustus III of Poland, contributed to the town’s reconstruction. Sułkowski rebuilt the church and built a hunting palace for the king. The town was destroyed yet again during the Kościuszko Uprising (1794), Austro-Polish War (1809), and during national uprisings in 1830-31 and 1863-64.

At the turn of the 18th and 19th centuries, during the Prussian reign (after the Second Partition of Poland in 1795 in Southern Prussia), German settlers appeared in Piaseczno. The town went through a period of prosperity during the time of Congress Poland. In 1820, there was a brewery there, two distilleries, three tanneries, and a few mills. In 1823, the brick town hall was rebuilt, the roads were cobbled, the streets were lit and both the town and the suburbs were irrigated. In 1869, the Russian occupant deprived Piaseczno of its city rights (it regained them in 1916). The town underwent another revival towards the end of the 19th century. In 1898, a narrow gauge railway linking Piaseczno with Warsaw was launched.

In the 20th century, the town started to acquire features typical of a holiday resort. In independent Poland it became part of the Warsaw county of Warsaw Province. In 1934, it gained a railway connection with Radom and Warsaw. Large factories of the Local Warsaw Railways were built. In the years 1952-1975 and again after 1999, Piaseczno was a county centre in Warsaw Province (currently Masovian Province). Nowadays, the factor that has considerable influence on the life and quick rise of the town's population is its location in the Warsaw agglomeration - in 2013, Piaseczno's population was more than 41,000[[refr:|Miasta polskie w tysiącleciu, S. Andrzejewski, M. Siuchniński et al. (eds.), vol. 2, (1967), 497-498.]].