Hyaluronidase (hyalase) has been routinely incorporated with etorphine HCl (M99) during immobilization of herbivores particularly those with thick skin to enhance drug absorption and decrease the induction time. This study evaluated retrospectively the usefulness of hyalase for immobilizing African elephants. Two protocols, one containing M99 (mean total dose 12.8±2.26mg; range 10-15mg) and hyalase (total dose 2500IU) and another M99 alone (mean total dose 12.7±1.84mg; range 10-15mg) were evaluated for first immobilization signs and induction time. Each treatment group consisted of twenty health adult elephants with equal sexes. Results showed the mean induction time were shorter in females than males immobilized using M99 mixed with hyalase or M99 alone but not statistically significant (P>0.05). Similarly, the mean time for the two parameters in the two treatment groups regardless of sex were not statistically significant (Mann-Whitney U test 184.0; p=0.66). Irrespective of the sex, the overall difference in induction time for the two treatment groups did not exceed two minutes. Retrospective analyses of other studies using M99 and varying doses of hyalase (from 1500 to 5000 IU) appear not to shorten the time to first observed signs of immobilization and subsequent induction time. The present study did not observe the clinical significance of incorporating hyalase in M99 for elephant immobilization. However, more data is required to demonstrate any difference in induction time and efficacy of the drug combination of M99 with hyalase.