His talent was first discovered by the Ostrowscy family of landed gentry, who sponsored his art studies in Warsaw in 1885 under the tutorage of Jan Kryński and Ludwik Pyrowicz.

Soon later, Laszczka received a scholarship from the Polish Society of Visual Arts (Towarzystwo Sztuk Pięknych) called "Zachęta" and went to Paris in 1891.

Among his students were: Stanisław Jackowski, Bolesław Biegas, Xawery Dunikowski, Ludwik Konarzewski, Franciszek Mączyński, Olga Niewska[4] and Zofia Baltarowicz-Dzielińska.

His connection with the Art Nouveau movement emanated from statues such as "W nieskończoność" (Eternally) from 1896–1897, "Nostalgia" (1903) and - inspired by Edvard Munch - "Krzyk" (The Scream) from 1902.

[12] In the late period of his artistic career, he became interested in fired ceramics, with subject matter drawn from religious, folk and animal themes.