Habitat fragmentation is one of the greatest threats to biological diversity. Here, I review the demographic and genetic consequences of habitat fragmentation for plant populations. Many empirical studies over the past 15 years suggest that seed production is markedly reduced with fragmentation, and that edge effects affect many fitness components, such as seedling recruitment and herbivory. In addition, fragmentation is often associated with reduced genetic diversity and elevated inbreeding, reducing offspring performance. These effects are expected to limit fecundity of remnant populations, although the consequences for long-term viability are not always apparent, particularly for long-lived species. Although several demographic studies have demonstrated that smaller populations are more likely to become extinct, the causes of extinction usually remain unknown. We still lack long-term demographic data to examine whether and how habitat fragmentation limits population growth of remnant populations.