This paper investigates whether the semantic and phonological levels in speech production are specific to spoken languages or universal across modalities. We examined semantic and phonological effects during Catalan Signed Language (LSC: Llengua de Signes Catalana) production using an adaptation of the picture-word interference task: native and non-native signers were asked to sign picture names while ignoring signs produced in the background. The results showed semantic interference effects for semantically related distractor signs and phonological facilitation effects when target signs and distractor signs shared either "Handshape" or "Movement" but phonological interference effects when target and distractor shared "Location". The results suggest that the general distinction between semantic and phonological levels seems to hold across modalities. However, differences in sign language and spoken production become evident in the mechanisms underlying phonological encoding, shown by the different role that "Location", "Handshape", and "Movement" play during phonological encoding in sign language. (Contains 2 tables and 1 figure.)