<jats:p> This study was aimed at investigating the alkaloids present in the leaves of Dehaasia hainanensis. Thirteen isoquinolines were isolated and characterized. Of these, four aporphines [(+)-laurolitsine, (+)-corydine, (+)-laurotetanine and (+)-lindcarpine], two morphinans [(-)-sinoacutine and (-)-ocobotrine], four benzylisoquinolines [(+)-reticuline, (+)-roefractine, (+)-reticuline N-oxide, and O-methylarmepavine], and one bisbenzylisoquinoline [(-)-N,N'-dimethyllindoldhamine] are reported for the first time from Dehaasia species. The structures were elucidated by spectral analysis.