After law studies at Vilnius University, he moved to Warsaw where he worked at the state censorship office until retirement in 1857.
Nezabitauskis was born in Baidotai [lt] near Salantai, Samogitia, then part of the Russian Empire, to a family of free peasants.
Born as Zabitis, he followed the example of his elder half-brother and Polonized his name to Niezabitowski and adopted the Lubicz coat of arms to appear to be from the Lithuanian nobility.
[3] Together with professor Ivan Loboiko [ru], Nezabitauskis traveled across Samogitia collecting information on Lithuanian dialects.
[2] In 1824, Nezabitauskis published a primer of the Lithuanian language entitled Naujas moksłas skaytima diel maźū waykū Źemaycziu yr Lietuwos (New Education on Reading for Little Children of Samogitia and Lithuania).
[3] It was an important addition not only because it was one of the first publications of Lithuanian folklore but also because earlier primers included only religious texts (catechism and prayers) and a poem praising corporal punishment in schools.
[2] Dionizas Poška highly praised the primer for its language purity, good spelling, and style[7] and wanted to publish a Polish translation.
[2] Nezabitauskis continued to update the bibliography and in 1829 prepared a 14-page list that he hoped but failed to publish as a separate booklet.
[2][3] In letters to professor Michał Wiszniewski and Simonas Daukantas, Nezabitauskis claimed authorship of an unfinished manuscript of a Lithuanian–Polish dictionary and of a 75-page booklet on beekeeping translated from a Polish work by Jan Krzysztof Kluk.