The present paper describes a novel method for the quantitative determination of inorganic arsenic (iAs) in food and feed of marine origin. The samples were subjected to microwave-assisted extraction using diluted hydrochloric acid and hydrogen peroxide, which solubilised the analytes and oxidised arsenite (AsIII) to arsenate (AsV). Subsequently, a pH buffering of the sample extract at pH 6 enabled selective elution of AsV from a strong anion exchange solid-phase extraction (SPE) cartridge. Hydride generation atomic absorption spectrometry (HG-AAS) was applied to quantify the concentration of iAs (sum of AsIII and AsV) as the total arsenic (As) in the SPE eluate. The results of the in-house validation showed that mean recoveries of 101–104% were achieved for samples spiked with iAs at 0.5, 1.0 and 1.5 mg·kg−1, respectively. The limit of detection was 0.08 mg kg−1, and the repeatability (RSDr) and intra-laboratory reproducibility (RSDIR) were less than 8% and 13%, respectively, for samples containing 0.2 to 1.5 mg kg−1 iAs. The trueness of the SPE HG-AAS method was verified by confirming results obtained by parallel analysis using high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry. It was demonstrated that the two sets of results were not significantly different (P < 0.05). The SPE HG-AAS method was applied to 20 marine food and feed samples, and concentrations of up to 0.14 mg kg−1 of iAs were detected.