The determination of lanthanides in six soil and six sediment reference materials was investigated by inductively cou- pled plasma mass spectrometry (ICPMS) using fusion and acid digestion. In the present study, the samples were fused with lithium metaborate (LiBO2) and lithium tetraborate (Li2B4O7). In the case of acid decomposition, the samples were digested with a mixture of hydrofluoric acid (HF) and perchloric acid (HClO4). For both cases, 1:1 HNO3 was used for extraction of the decomposed samples. The internal standard (10 ppb indium) was used to take care of the signal drift of the instrument. The measurement was done using a 1 ppb matrix- matched calibration standard prepared from lanthanide salts. The effect of different combina- tions of fusion flux was investi- gated. A detailed study was also made taking a different isotopic mass for measurement of the lan- thanides. Both dissolution techniques were evaluated. Uniform and good recovery of the lanthanides was observed using a fusion mix- ture containing 35% lithium tetraborate and 65% lithium metaborate. The accuracy of the methodology was excellent. Extraction of the lanthanides from the soil and sediment sam- ples by acid digestion method varied from 80–105%. Precision and accuracy in case of the fusion method was very good. The limit of quantitation (10σ) for the determination of the lan- thanides in soil and sediment samples was in the ppb range.