Protein N-ɛ-acetylation is recognized as an important modification influencing many biological processes, and protein deacetylase inhibitors leading to N-ɛ-hyperacetylation of histones are being clinically tested for their potential as anticancer drugs. In contrast to N-ɛ-acetyltransferases, the N-α-acetyltransferases transferring acetyl groups to the α-amino groups of protein N-termini have only been briefly described in mammalians. Human arrest defective 1 (hARD1), the only described human enzyme in this class, complexes with N-acetyltransferase human (NATH) and cotranslationally transfers acetyl groups to the N-termini of nascent polypeptides. Here, we demonstrate that knockdown of NATH and/or hARD1 triggers apoptosis in human cell lines. Knockdown of hARD1 also sensitized cells to daunorubicin-induced apoptosis, potentially pointing at the NATH–hARD1 acetyltransferase complex as a novel target for chemotherapy. Our results argue for an essential role of the NATH–hARD1 complex in cell survival and underscore the importance of protein N-α-acetylation in mammalian cells.