Starting his career in 1982, he formed the famous Finnish rock band Kolmas Nainen in 1982.

In 2009, the highly popular Kolmas Nainen returned with two new studio albums and great commercial success.

Hanhiniemi, a prolific singer, songwriter has been involved in writing songs for his own bands, Kolmas Nainen, Pauli Hanhiniemen Perunateatteri, Hehkumo, as well as many other Finnish musical acts such as Edu Kettunen, Juliet Jonesin Sydän, Kerkko Koskinen, Anna Eriksson, Hauli Bros amongst others.

The band was fronted by Pauli Hanhiniemi and came to fame after taking part in the 1984 Rockin SM-kisoissa, a rock music competition.

The band was formed of: Pauli Hanhiniemi and Hehkumo released two studio albums: Muistoja tulevaisuudesta in 2006 with singles including "Suvisivakointia / Hurja poika", "Suolammen vettä" and "Tähtiin kirjoitettu".