This presentation explains the resistance to acaricides in ticks is recognized through failure to control the ticks rather through early detection of resistance in the ticks, the larval packet test currently in use takes a long time to obtain what are sometimes ambigous results. Thus it is necessary to identify and characterize the mechanism(s) of resistance so that a rapid test to identify ticks resistant to the acaricides can be developed. Acaricide resistance in Boophilus spp ticks is a global problem requiring inmediate and increased research to understand the process of resistance development. Resistance of ticks to several pyrethroids acaricides have been correlated to high levels of esterase, suggesting hydrolysis by enzymes in the degradation. A process of esterase-induced detoxification has been proposed to produce resistance during the ticks exposure to acaricides. Small quantities of esterases are normally the expression of at least two different esterases, suggesting an overexpresssion similar to that found in other pesticide resistant arthropods