The sorting of eukaryotic proteins to various organellar destinations requires receptors that recognize cargo protein targeting signals and facilitate transport into the organelle. One such receptor is the peroxin PEX 5, which recruits cytosolic cargo carrying a peroxisome‐targeting signal ( PTS ) type 1 ( PTS 1) for delivery into the peroxisomal lumen (matrix). In plants and mammals, PEX 5 is also indirectly required for peroxisomal import of proteins carrying a PTS 2 signal because PEX 5 binds the PTS 2 receptor, bringing the associated PTS 2 cargo to the peroxisome along with PTS 1 cargo. Despite PEX 5 being the PTS 1 cargo receptor, previously identified Arabidopsis pex5 mutants display either impairment of both PTS 1 and PTS 2 import or defects only in PTS 2 import. Here, we report the first Arabidopsis pex5 mutant with an exclusive PTS 1 import defect. In addition to markedly diminished GFP ‐ PTS 1 import and decreased pex5‐2 protein accumulation, this pex5‐2 mutant shows typical peroxisome‐related defects, including inefficient β‐oxidation and reduced growth. Growth at reduced or elevated temperatures ameliorated or exacerbated pex5‐2 peroxisome‐related defects, respectively, without markedly changing pex5‐2 protein levels. In contrast to the diminished PTS 1 import, PTS 2 processing was only slightly impaired and PTS 2‐ GFP import appeared normal in pex5‐2 . This finding suggests that even minor peroxisomal localization of the PTS 1 protein DEG 15, the PTS 2‐processing protease, is sufficient to maintain robust PTS 2 processing.