The objective of this study was to assess whether there was a periparturient rise in the faecal egg output of a population of North African gazelles (Gazeia dama mhorr) kept in captivity in Almeria, southern Spain. In one experiment faeces were collected from 47 female gazelles on three days in winter, in November and December 1995 and January 1996; in a second experiment faecal samples were collected from nine pregnant gazelles at weekly intervals from July 1996 to June 1997. The mean trichostrongylid faecal egg counts were significantly higher (P<0.05) in the periparturient gazelles than in the pregnant and nonpregnant animals only when the births took place in winter. Other factors, including the gazelle's age, its level of inbreeding, the number of previous births, and its trichostrongylid egg output at the beginning of the study did not affect whether it showed a periparturient rise. The parasites responsible for the rise were different in the two experiments.