The dynamics of photoinduced electron transfer has been investigated in DNA hairpins possessing a stilbenedicarboxamide (Sa) electron acceptor, a guanine (G) primary donor, and two adjacent guanines (GG) as secondary donors. Hole transport from G to GG across a single A is more rapid than across AA or T by factors of 20 +/- 7 and 40 +/- 15, respectively. Intrastrand hole transport across a single A is more rapid than interstrand transport by a factor of 7 +/- 3.