Aromatic and medicinal plants (AMP) are flora with a fragrant essence. The aim of this study is to identify the aromatic plants used by herbalists in three districts of the Departement des Collines. The method of data collection is based on ethnobotanical surveys of herbalists using the Dagnelli formula and pre-established survey questionnaires. The results of the survey of 300 herbalists identified 22 most commonly used aromatic plants, divided into 17 families and 21 genera. The most represented families are Lamiaceae (15%); Annonaceae (15%). Among the MAPs inventoried, the most cited and used are: Ocimum canum L. Ocimum gratissimum L.; Chenopodium ambrosioides L.; Hyptis suaveolens L.; Xylopia aethiopica (Dunal) A. Rich; Securidaca longepedunculata Fresen. MAPs treat 163 conditions identified in this study. Some of the AMP are used alone or in combination with other plants. AMP drugs are: leaves (64%), roots (23%). The ailments treated by the majority of AMP are: fever; tooth decay; conjunctivitis; constipation; haemorrhoids; hernia; inflammation; skin lesion; stomach ache; snakebite; causes of malaria; sores and painful periods. In view of the proven importance and different uses of AMP, it is necessary to study them further (ecology, distribution, and conservation status) in order to better prevent or cure human health.