Schmallenberg virus (SBV) is an Orthobunyavirus of the Simbu serogroup that has been recognized as the causative agent of a large outbreak in European ruminants. After its first detection in 2011, monitoring by serological analysis and real - time RT - PCR of SBV started in January 2013 in Croatia. Consequently, the presence of antibodies against SBV, as well real - time RT - PCR positive samples were recognized for the first time. Investigation of the SBV seroprevalence included 50 sera of cattle originating from different counties. Sera were checked by ID Screen ® , Schmallenberg virus Indirect, (ID.vet, France), a commercially available indirect enzyme - linked immunosorbent assay (ELISA) according to manufactures instructions. Antibodies against SBV were detected in 52% of tested sera. The highest prevalence was found in the northern part of Croatia. The presence of SBV - RNA in organ samples of aborted foetuses, stillbirths or malformed newborns was conducted by the use of real time RT - PCR assays developed by the Frie drich - Loeffler Institute, Germany. Altogether, 33 brain samples of aborted calves, at the 5 - 7 month of gestation, 1 brain from malformed newborn calf, 7 cow placentas, 8 brains of aborted lambs and 3 brains of aborted kids were examined. Six samples, five from calf brains and one from cow placenta, were positive for SBV - RNA, with cycle threshold (Ct) values of 28, 6 – 38, 8. A relative high percentage of seropositive animals, as well as SBV positive abortions, stillbirths and malformed newborn in the first mont hs of 2013 implicates that the infection has occurred in 2012.