Horizontal gene transfer (HGT) is a significant source of diversity in prokaryotes and a key factor in their genome evolution. Although similar processes have been postulated for eukaryotes, the validity of HGT’s impact remains contested, particularly between long distance related organisms like from different kingdoms. Among eukaryotes, the fungal subphylum Pezizomycotina has been frequently cited in literature for experiencing HGT events, with over 600 publications on the subject. We meticulously examine the proteomes of 421 Pezizomycotina species to identify potential instances of interkingdom HGT. Furthermore, we revisit the phylogenies of over 275 HGT candidates previously reported. Through manual scrutiny of 521 anomalous phylogenies, we ascertain that only 1.5% display patterns indicative of interkingdom HGT. Moreover, our novel interkingdom HGT searches within Pezizomycotina yield few new contenders, casting doubt on the prevalence of such events within this subphylum. Although our detailed examination of phylogenies suggested interkingdom HGT, the evidence for lateral gene transfer is not conclusive. Our findings suggest that expanding the number of homologous sequences could uncover vertical inheritance patterns that have been misclassified as HGT. Consequently, this research supports the notion that interkingdom HGT may be an extraordinary occurrence rather than a significant evolutionary driver in eukaryotic genomes.