The nucleotide sequences of the terminal regions of monomer replicative form DNA, a pivotal intermediate species in the replication of minute virus of mice, were determined. The left (3') terminus had a unique sequence on both strands and in both 3'-hairpin configurations. In contrast, the right (5') terminus was sequence heterogeneous and extended an additional 18 base pairs beyond that expected from the known sequence of the virion DNA. These data unambiguously establish the sequence complexity at the termini of both the single-stranded viral genome and the pool of replicative DNA. A comparison of the combined sequence information leads us to propose a modified rolling hairpin model for the replication of autonomous parvoviruses which is compatible with all available data.