The clonidine patch offers for the first time the unique possibility of a once-a-week transdermal therapy of hypertension due to direct absorption of clonidine through the skin. The present study investigates the efficacy and safety of the transdermal administration on a sample of the Italian population. 101 patients entered the study, 51 male, 50 female (mean age: 53 years, SD ± 10; range: 30–71 years), they were given clonidine by a therapeutical transdermal system as starting dosage. If blood pressure was not adequately controlled (DBP < 90="" or="" 10="" mmhg="" decreased="" from="" baseline="" value)="" the="" dosage="" was="" increased="" on="" a="" 2="" week="" basis="" assessment.="" the="" patients="" were="" then="" followed="" for="" 12="" months="" after="" the="" start="" of="" treatment.="" the="" decrease="" in="" both="" systolic="" and="" diastolic="" blood="" pressure="" continued="" up="" to="" one="" month="" after="" start="" of="" treatment="" and="" remained="" constant="" for="" at="" least="" 9="" months.="" a="" total="" of="" 70%="" of="" the="" patients="" were="" controlled="" by="" the="" antihypertensive="" treatment="" as="" monotherapy,="" while="" in="" 6%="" additional="" combination="" with="" a="" diuretic="" lead="" to="" blood="" pressure="" control.="" 5%="" of="" the="" patients="" showed="" no="" reduction="" in="" blood="" pressure="" at="" the="" end="" of="" the="" titration="" phase.="" 24="" (23%)="" patients="" complained="" of="" skin="" reaction;="" 21="" patients="" of="" these="" (ten="" male,="" eleven="" female)="" were="" withdrawn="" from="" the="" trial="" due="" to="" predefined="" skin="" reaction="" criteria.="" no="" serious="" side="" effects="" have="" been="" observed="" during="" the="" run="" of="" the="" study.="" no="" rebound="" phenomena="" occurred="" in="" the="" week="" after="" treatment="" discontinuation.="" it="" is="" concluded="" that="" the="" transdermal="" treatment="" of="" hypertcnsion="" with="" a="" clonidine="" containing="" transdermal="" system="" is="" therapeutically="" effective="" and="" probably="" associated="" with="" a="" high="" acceptability="" and="" increased="">