Six anthocyanins were isolated from the brownish-red flowers of Ipomoea purpurea. Cyanidin 3 sophoroside was identified as the parent anthocyanin. The other five anthocyanins are acylated derivatives with glucosylcaffeic acid and/or caffeic acid. The structures of three were unambiguously determined to be cyanidin 3-0-[2-0-(6-0-(trans-4-0-(6-0-(trans-3-O-(~-D-glucopyranosyl)-caffeoyl)-~-D-glucopyranosyl) caffeoyl)-~-D-glucospyranosyl)-~-D-glucopyranoside], cyanidin 3-0-[2-0-(6-0-(trans-caffeoyl)-fl-D-glucopyranosyl)-p-D-glucopyranoside] and cyanidin 3-O-[2-O-(~-D-glucopyranosyl)-6-O-(tru~~-caffeoyl)-~-D-glucopyranoside]. The remaining two pigments could not be determined because of their small yields. In these flowers, the major pigments are cyanidin 3-glucosylcaffeoylglucosylcaffeoyl-sophoroside, cyanidin 3-sophoroside and cyanidin 3-caffeoylsophoroside. They are considered to play an important role in producing the dusky colour of these petals.