We investigated volume and shape changes in the striatum (caudate, putamen, and nucleus accumbens) of 18 early-onset (EOAD) and 18 late-onset (LOAD) Alzheimer's Disease patients compared with 2 control groups age- and sex-matched to each patient group, and explored the relationship between striatal atrophy and apolipoprotein E (APOE) genotype. EOAD patients showed significant shape changes in the left and right ventral putamen (p < 0.05, corrected for multiple comparison with permutation tests). LOAD patients showed significant reductions in the left and right nucleus accumbens volumes (p < 0.05; Mann-Whitney test) and shape (p < 0.05; permutation test). Caudate abnormalities were detected in EOAD and LOAD patients in terms of local enlargements and reductions (p < 0.05 for the left and right, permutation test). When APOE was considered, significant differences were detected between LOAD ε4 carriers and noncarriers in the left and right caudate (p < 0.05, permutation test). These results suggest distinct patterns of striatal pathology in EOAD and LOAD patients, the dorsal striatum being involved in EOAD and the ventral striatum in LOAD.