The mining sector is often presented as a driver of economic growth. However, it has negative effects on flora and vegetation. This study aims to assess the structure and floristic diversity of the vegetation in the area of the SCB-Lafarge cement works of Onigbolo in the municipality of Pobè (southern Benin). The data were collected by means of floristic surveys carried out in 60 rectangular plots of 500 m2 including 30 in abandoned quarries and 30 in non-exploited areas. The vegetation of abandoned quarries has been distinguished into 2 plant formations and that of unexploited areas comprises 4 types of vegetation. A total of 304 species have been recorded, including 180 in quarries and 248 in non-exploited areas. The specific richness varies from one plant formation to another in the two zones. The average specific diversity (4.63 bits) of quarries is lower than that of non-exploited areas (5.62 bits). The density of the woody plants varies from 90 to 132 stems / ha in the quarries and from 160 to 268 stems / ha in the non-exploited areas. The basal area is 2.80 m2 / ha in the quarries and varies from 5.40 to 17.16 m2 / ha in the non-exploited areas. The vegetation of abandoned quarries is floristically less diversified and less structured than that of unexploited areas. The exploitation of limestone therefore participates in the reduction of flora diversity and regressively affects the density and basal area of the woody stand.