Recent genomic studies revealed that mitochondria from mistletoe species appear to lack a major amount of genes, indicating a possible loss of the NADH ubiquinone oxidoreductase (complex I) which forms an essential part of the mitochondrial Oxidative Phosphorylation System (OXPHOS). This dataset (mascot generic file (mgf) are gel-based proteomic data: Protein spots from a 2D Blue native - SDS Polyacrylamide gel were carbamidomethylated and in gel digested with trypsin, peptides were extracted and measured with an online Easy nano Liquid Chromatography (Thermo Scientific) - micrOTOF Q II mass spectrometer (Bruker Daltonics) setup. Data were searched with MASCOT (www.matrixscience.com) against an in-house Arabidopsis and Viscaceae database (not shown, see Senkler et al., 2018, Current Biology) and used to build a reference map of the mitochondrial protein complex proteome from European mistletoe, Viscum album. The reference map (available at www.gelmap.de/1327) gives biochemical evidence for a lack of mitochondrial complex I as well as a unique protein (super) complex composition of the oxidative phosphorylation system (OXPHOS) in Viscum album.