Toluene and toluene-containing volatile substances are the most widely abused solvents with demonstrative addictive potential in humans. Several data indicate that as a result of toluene misuse alterations in learning and memory in organisms of different age take place. But because of differences in species, length of exposure, dose or rate of administration, it is not always possible to conclude whether adolescent experience results in changes in learning and memory are comparable to that seen in adults. The present study has been undertaken to determine whether toluene chronic exposure provokes immediate and/or persisting effect on exploratory behavior and recognition memory in open field in adolescent and adult rats. We exposed male Wistar rats at ages P 28-32 (adolescents) and P 70-75 (adults) to 2000 ppm inhaled toluene for 40 days. The immediate and persisting effects of toluene misuse (immediately after the end of toluene chronic inhalation and 90-day after the end of toluene chronic inhalation, correspondingly) were evaluated. Experimental protocol was approved by Animal Studies Committee of I. Beritashvili Center of Experimental Biomedicine. The major findings are: (1) toluene misuse alters exploratory activity and recognition memory in adolescent and adult rats; (2) the level of alterations depends upon the postnatal age of testing animals. In particular: in adolescent rats the most significant behavioral alterations were observed by the day following toluene chronic exposure. These alterations do not progress significantly during abstinence period: some altered parameters were almost the same as observed the day following immediately after toluene misuse and others were very close to observed in control animals. Therefore, in adolescent rats the most expressed was immediate effect of toluene misuse. Contrary to it: in adult rats most alterations significantly progress during 90 d period of abstinence. So, in these animals more substantial was persistent effect of toluene chronic exposure. On the bases of our data it is possible to suggest that adolescent rats may show partial recovery from once the toluene toxic effect no longer persists.