|Date of birth||19 June 1986|
|Place of birth||Athens, Greece|
|Height||1.71 m (5 ft 7 1⁄2 in)|
|2010||→ Olympiakos Volou (loan)||9||(3)|
|2012–2013||FK Khazar Lankaran||21||(6)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 9 March 2014.
† Appearances (Goals).
Ethnikos Piraeus, PAS Giannina and Olympiakos Volou
In July 2008, Sialmas signed a two-year deal with Ethnikos which lasted for only one. Then, Giannina approached him and signed him, as PAS thought that he was an extremely talented striker. Giannina fans loved him, something that intrigued the Volos club and that led Olympiakos to borrow him for 6 months.
On the 30/5/11 Sialmas signed a three-year deal with AEK Athens on a free transfer keeping him at the club until 2014. Sialmas also chose the number 11 Jersey previously worn by former AEK player Demis Nikolaidis. His skills and movements reminded ΑΕΚ fans of the legendary Demis Nikolaidis and many of them compared the two. Sialmas scored two goals against Levadiakos and helped AEK to win 0-2. He was also given the MVP award.
In the summer of 2012 Sialmas signed for Azerbaijan Premier League side Khazar Lankaran on a one year contract. Sialmas scored six goals in 24 games in all competitions for Khazar, as well as reaching the 2012–13 Azerbaijan Cup final. In the final the game went to penalties after finishing 0-0 after extra time, Sialmas took and missed the opening Khazar penalty, resulting in Neftchi Baku winning 5-3 on penalties. Sialmas was released at the end of his contract in the summer of 2013.
- "Dimitrios Sialmas and Vanderson Skarduelli are officially in "Khazar Lankaran")". http://lankaranfc.com/en. Retrieved 27 September 2013.
- "Σιαλμάς και επίσημα στον Πλατανιά". sport24. Retrieved 12 December 2013.