African swine fever (ASF) is one of the most complex livestock diseases. The significant losses that it causes, coupled with the lack of a vaccine against ASF virus and the possible resemblance with other swine hemorrhagic diseases, make early detection and laboratory diagnosis essential for controlling and managing the disease. All the techniques currently used to diagnose ASF have been fully validated showing high sensitivity and specificity to detect both antigen and antibodies against all 22 known genotypes; and enable the correct diagnosis of ASF in all possible epidemiological situations. Because no vaccine is available, the presence of antibodies always indicates previous infection, and serological diagnosis must always be performed in parallel with antigen detection to increase the sensitivity and specificity of the analyses. Recent developments in ASF diagnosis, specifically the new field diagnostic tests, have improved and facilitated the likelihood of ASF early detection, essential to fighting the disease.