Human sperm for use in artificial insemination with husband's semen (AIH) were prepared by two methods: the monolayer Percoll method and the discontinuous Percoll density gradient of four steps. The former focused mainly on the oligozoospermic semen concentration, with the sperm concentration and motility being improved 4.29 +/- 3.7 times and 1.92 +/- 1.1 times, respectively (n = 41). The latter was used principally for the selective isolation of forward motile sperm, with the sperm motility being increased from 42.3 +/- 29.5% to 76.3 +/- 11.0% after centrifugation. The clinical application of these procedures resulted in 35 (the monolayer Percoll method) and 10 (the discontinuous Percoll density gradient) successful deliveries with greater enhancement of sperm qualities. The number of females was predominate over the males in the delivered cases: 31:34 (100:45.1) females to males.