Cranial and post-cranial variation is described for a large series of specimens of spectacled porpoise from Argentina and compared with that for specimens from other areas of the Southern Hemisphere. Condylobasal length in 54 adult skulls was 276-424. Tooth counts were 16-26 and 17-23 in the upper and lower jaws, respectively. Total number of vertebrae (n = 20) was 66-70. The rostrum may be relatively smaller in the Auckland Islands than in other regions.