The fatty acid composition of the moss Rhytididelphus squarrosus (Hedw.) Warnst. (Hylocomiaceae) collected in Germany during winter time was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Nine fatty acids were identifi ed in its chloroform:methanol extract 1:1: arachidonic acid (30.7%), α-linolenic acid (19.1%), linoleic acid (15.1%), cis-5,8,11,14,17-eicosapentaenoic acid (14.4%), palmitic acid (11.9%), cis-8,11,14- eicosatrienoic acid (4.1%), oleic acid (2.3%), γ-linolenic acid (1.4%) and stearic acid (1.0%). Th e results indicate that this plant species can be a good source of arachidonic acid collected during the winter.Sastav viših masnih kiselina mahovine Rhytididelphus squarrosus (Hedw.) Warnst. (Hylocomiaceae), sakupljene u Nemačkoj za vreme zimskog doba, preliminarno je ispitivan GC i GC-MS analizom. U njenom ekstraktu hloroform: metanol 1:1 identifikovano je devet viših masnih kiselina: arahidonska kiselina (30.7%), α-linolenska kiselina (19.1%), linolna kiselina (15.1%), cis-5,8,11,14,17-eikosapentaenska kiselina (14.4%), palmitinska kiselina (11.9%), cis-8,11,14-eikosatrienska kiselina (4.1%), oleinska kiselina (2.3%), γ-linolna kiselina (1.4%) i stearinska kiselina (1.0%). Dobijeni rezultati ukazuju da je ova biljna vrsta dobar izvor arahidonske kiseline u ispitivanom vremenskom periodu