The 45-year-old had previously worked on the national team as an assistant.
Štelmahers had worked as the head coach of Latvian basketball club Ventspils for several seasons, but this off-season was appointed the head coach of Estonian basketball club Tallinn Kalev/Cramo.
Štelmahers has also coached clubs in Lithuania and Poland in the past as well.
In his playing career, Štelmahers played for top clubs in Europe as well as the Baltics, including Vilnius Lietuvos Rytas, Wroclaw Slask, Istanbul Ulker, Ljubljana Olimpija, Veroli Prima and ASK Riga to name a few.
He also represented Latvia at four European Championships and played in over 140 games for the Latvian national team.
The previous head coach of the Latvian national team Arnis Vecvagars stepped down after Latvia failed to qualify for this year's FIBA World Cup.