More than half of all elderly people have some degree of cerebral white matter lesions. However, the rate of progression of these lesions is uncertain. We aimed to assess the progression of lesions in community-dwelling volunteers aged 50-75 years without neuropsychiatric disease. We used MRI to grade and measure the total volume of white matter lesions in 296 volunteers at baseline, 3 years, and 6 years. 58 participants with no lesions and 123 with punctate abnormalities at baseline had a low tendency for lesion progression, whereas 14 participants with early confluent and nine with confluent lesions underwent median increases of 2.7 cm(3) (IQR 0.5-5.9) and 9.3 cm(3) (7.1-21.0), respectively, in lesion volume at 6 years. Lesion grade at baseline was the only significant predictor of lesion progression (p<0.0001). Punctate white matter lesions are not progressive and are thus benign, whereas early confluent and confluent white matter abnormalities are progressive, and thus malignant.