Seven species of the Acantholaimus are described. Acantholaimus vermeuleni sp.n. is characterised by labial and cephalic sensilla that are located at the same level, two post amphidial setae on the dorso-lateral side and a poorly developed stoma without distinct teeth. Acantholaimus verscheldi sp.n. is characterised by a narrow elongate pharyngeal region, a long stoma with distinct teeth and short (4-7 µm) cephalic sensilla. Acantholaimus heipi sp.n. is characterised by a narrow elongate pharyngeal region, well developed teeth in the stoma and long cephalic sensilla (11-13 µm). Acantholaimus elegans Jensen 1988 has a narrow anterior pharyngeal region that increases in width posteriorly, it has setae before and after the amphids on both sides and stoma with well developed teeth. Acantholaimus gathumai sp.n. is characterised by long cephalic (10-15 µm) and somatic (8-10 µm) setae and lateral differentiation with fine dots (5-7 µm in width). Acantholaimus geraerti sp.n. has long cephalic sensilla (15-19 µm) and narrow (4-6 µm) distinct lateral differentiation. Acantholaimus invaginatum sp.n. is characterised by very long cephalic setae (16-21 µm), several setae at the pharyngeal region and wide lateral differentiation with fine dots, often the stoma is invaginated.