Population introduction is frequently attempted to promote rare plant conservation but there is little evidence to evaluate its effectiveness. We measured size structure, survival, growth, and recruitment in three 20-year-old introduced populations of the endangered shrub Conradina glabra, an endemic in upland longleaf pine habitat in the Florida Panhandle, and compared these with measurements from three natural populations. We also quantified inbreeding depression from hand pollinations in two populations and incorporated its consequences for seed production and germination into demographic projections. Individuals in introduced populations, which had been subjected to recent prescribed fire, grew nearly three times faster and produced more than twice as many recruits per individual, but suffered 3.7% greater mortality than individuals in wild populations growing in habitat where fire was suppressed. Demographic matrix projections based on our data predict that introduced populations would grow at least as fast as the naturally occurring populations. Inbreeding depression was strong (δ = 0.887, 0.65 in one introduced and one wild population, respectively) but was predicted to threaten population growth rates only if selfing were to increase substantially. Our results, along with previous evidence for population growth after the initial introductions and persistence for over 25 years, illustrate the potential for well-designed introduction combined with appropriate management to contribute to rare plant conservation.