Completion of the life cycle of Hyalomma impeltatum Schulze & Schlottke required an average of 108 d at 26 +/- 1 degree C, 92-96% RH, and 12:12 (L:D) photoperiod. Weights of unfed larvae, nymphs, and females were 0.02, 0.16, and 15.4 mg, respectively, and increased 23-, 164-, and 55-fold, respectively, as a result of feeding on guinea pigs. Larvae and adults exhibited host-seeking behavior less than 1 d after hatching and molt, respectively; nymphs exhibited host-seeking behavior 2.9 d after molt. The mean (+/- SE) feeding period as larvae was 5.9 (+/- 2.23) d, nymphs 6.7 (+/- 1.10) d, and females 8.0 (+/- 0.19) d. Larvae molted 12.4 (+/- 0.26) d and nymphs molted 28.9 (+/- 0.22) d after engorgement. A sex ratio of 1.26:1 female/male was determined from emerged adults. Females began oviposition 8.9 (+/- 0.22) d after engorgement and produced 10,680 (+/- 300) eggs per female. Egg hatch was 84% (+/- 2.68) after an incubation period of 32.8 (+/- 0.19) d. Females converted 55% of engorged weight into eggs and produced 12,475 (+/- 188) eggs/g of engorged body weight. A freshly laid egg on the first day of oviposition weighted 47.7 (+/- 0.65) micrograms. An inverse relationship between egg weight and rate of egg production was observed.