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Because Mediterranean ecosystems are prone to fire, their soils are expected to contain relevant amounts of black carbon BC; nevertheless, quantitative information is scarce. Herein, we provide data on the abundance of BC in the surface soil uppermost 5 cm of shrubland plots on old agricultural fields diversely affected by fires 0, 1, or 2 wildfires in the last 25 y and with contrasted landuse histories either never cropped, early abandoned, or recently abandoned. Black C and black nitrogen BN were quantified in the surface horizon 0–5 cm as the residue of lowtemperature dichromate oxidation, after previous destruction of mineral matter with HF. The obtained amounts of BC ranged from 0.73 to 10.32 g kg dw–1mean: 3.07, which corresponds to an average of 8.62 of the total organic C, while the amounts of BN ranged from 21.5 to 373.0 mg kg dw–1mean: 97.1, or an average of 4.30 of the total N of the samples. Repeated fires did not consistently increase either the BC or the BN amounts. BlackC and especially BN accumulation seems related to fine silt, whereas the effect of clay is unclear. Even though the amounts of BC obtained in this study are slightly higher than those from other ecosystems, including Mediterranean broadleaved forests, overall they are far from the very high values reported in the literature for chernozems from Germany or Canada. Thus, on the whole, in Mediterranean shrublands affected by wildfires, BC does not seem to be a dominant fraction in the soil organic C.