In the case of Hungarian composer and ethnomusicologist László Lajtha (1892–1963) discovering the manifold potentials in a symphonic orchestra linked strongly with the composition of works for stage and screen. Nevertheless, it clearly makes sense to examine the long-term relations Lajtha had with the film as a genre, by searching for common features in the structure of his music composed for films and his symphonies. Much of the musical material in Lajtha’s Third Symphony is similar to those he used in his 1948 film music for Murder in the Cathedral. The similarity gains more complexity if one takes into consideration that the Third Symphony was marked by the composer as the starting point in a monumental, five-fold symphonic cycle composed through the 1950s. The article makes an attempt to explore the thematic and motivic relationship between the Third Symphony, the Variations and the film score Murder in the Cathedral by analysing the musical material and the structure, and by searching for correlation between the audible and visual effects of the music Lajtha used in the movie scenes. This kind of examination may offer a new perspective on the sources of inspiration that shaped Lajtha’s workmanship and it also gives some important information about his way of thinking about music.