Ecological preferences and population status of the New Guinean palm Sommieria leucophylla in Salawati island were documented at six different sites, covering a wide range of habitat types. The population of S. leucophylla in this island appears to be one of the largest populations occurred in the region, implying the conservation significance. Population sizes were dominated by young plants, indicating a growing population. The stem height class distribution showed a preponderance of individuals in the juvenile stage class and a strong right hand skew typical of populations in which recruitment and mortality were continuous and density dependent, rather than episodic. The palm preferred specific habitat types, where river bank and intact forest became the most suitable habitat. The species seemed to be sensitive to disturbance and changes in water table leading to a narrow ecological tolerance. Mortality was higher among the early stages and there was only very little recruitment in disturbed site and even no recruitment in converted forest. To conserve the most important remaining populations of the endemic palm, it is crucial to protect the most suitable sites in the reserve.