We assessed the value of requesting a second semen sample provided within 1 hour of the first in cases of unacceptable ejaculate quality (compared to previous occasions) or very poor semen characteristics. The study population consisted of 109 males with severe oligo-terato-astenospermic (OTA) syndrome in an assisted reproduction program. Semen volume, sperm count and sperm motility were recorded in the first and second samples with a Makler Counting Chamber before sperm processing, and total motile sperm in the ejaculate was calculated. Differences in sperm parameters between the consecutive samples were determined by paired-sample t test. In 36 cases (33%) the second sample was found to be superior in quality to the first and was therefore used for the fertilization process. Of the 12/109 cases in which the first ejaculate demonstrated no motile sperm, five (41%) had detectable motile sperm in the second (total 0.1 x 10(6), 0.2 x 10(6), 0.3 x 10(6), 8.4 x 10(6) and 20.8 x 10(6)). We conclude that a request for second ejaculate immediately after the first in males with poor semen quality or no detectable motile sperm can yield a better sample in a significant percentage of cases. Using this method, clinicians can avoid the utilization of elaborate sperm processing techniques and the need for unnecessary micromanipulative fertilization.