To evaluate the effect of the immersion of engorged larvae and nymphs of Amblyomma dubitatum experimentally fed on rabbits, the ticks were collected and formed control groups, without immersion, and groups witch were immersed by 24, 48, 72, 96 hours and, for engorged larvaes, by eight weeks, in test tubes containing distilled water. During all experiment ticks were kept at 27 +/- 1 degrees C, 80 +/- 10% RU and scotophase The parameters evaluated were: pre-ecdysis, ecdysis and moulting periods; and ecdysis and mortality percentages. When compared with the control group, the effect (p<0,05) of immersion varied intra and inter stages. Apparently, immersion was less deleterious to A. dubitatum in comparison with A. cajennense and R. sanguineus from neotropical region, thus reflecting a long host relations with the capybara, its primary host.