This study was done to determine the effect of Cuminum cyminum crude extract on the reproductive performance of engorged female Hyalomma anatolicum ticks, and on directly treated eggs from untreated female ticks. A locally made device was used to enable exposure of ticks and eggs to the vapour of the volatile essential oil. The concentration used was 0.75% based on results of a previous study. Of treated female ticks, insignificant effect (P≥ 1.0) was reported on the pre-hatching period, and on the egg conversion rate (P≥ 0.5). Significant effect (P≤ 0.04) was reported on the pre-oviposition period, while on hatchability the effect was highly significant (P≤ 0.001). For directly treated eggs, significant effect (P≤ 0.01) was reported on the pre-hatching period, while the effect on hatchability was highly significant (P ≤ 0.001).