The fisheries catch statistics that member countries report annually to the Food and Agriculture Organization of the United Nations were compared, for the years 1950 to 2010, with ‘reconstructed’, and more likely catch data from the Mediterranean coasts of mainland Spain, France, Italy and Turkey. Reconstructed catches were 2.6 times higher than those submitted to the FAO by these countries in the 1950s, and 1.8 times higher since 2000. If discarded by-catch is ignored they were 2.3 and 1.6 times higher, respectively. The contributors to the reconstructed catch from 1950 to 2010 were large-scale industrial fisheries (46%), discards (29%), artisanal fisheries (10%), recreational fisheries (9%) and subsistence fisheries (6%). The non-reported catch was high in all fishing sectors, including industrial, artisanal and recreational fisheries. The non-inclusion of discards in national and FAO statistics undermines the transition to ecosystem-based fisheries management, but needs to be overcome, as discards must be tracked before discarding itself is eliminated. The systematic underestimation of small-scale fisheries is part of a global phenomenon that will have to be overcome if the potential of these fisheries for sustainable exploitation of coastal systems is to be realized, perhaps in the context of reducing overall fishing capacity, which is excessive in the Mediterranean Sea as elsewhere in the world.