The purpose of the paper is to review relevant geotechnical site investigation methods used to identify and characterise organic soils and peat and summarise some existing experience on their use. A brief overview of equipment used at terrestrial sites where these soils are present will be given first, including notes on devices such as piezocone (CPTU), piezocone with seismic receivers (SCPTU), T-bar and piezoball penetrometers. Some characteristics of peat observed from these study sites will be given including index properties, notably loss on ignition (LOI), specific descriptions of peat properties based on the von Post system, 1D compressibility and shear strength. Some examples will then be given for organic soils encountered at offshore sites. Organic soils and peat are often characterised by low corrected cone resistance (qt) and high friction ratio (Rf) from the piezocone test (CPTU). Previous experience has shown that more decomposed / amorphous peat and organic soils have higher generated pore pressures (u2) and pore pressure parameter (Bq) than fresher / fibrous material. A tentative relationship also appears present between von Post ‘H’ and Bq. These previous findings will be explored with new data along with some new thoughts. Recently developed Soil Behaviour Type (SBT) charts from the Netherlands will be trialled on organic soils and peat from other areas including for offshore sites. Piezoball testing will be shown to be useful in peat giving smoother profiles than CPTU and possibly more representative of the peat mass as a whole. Unfortunately it would seem that it is not always easy to distinguish between peat and underlying soft soils using CPTU alone. Therefore it would appear that inclusion of CPTU “add on” device particularly a seismic element to yield shear wave velocity (Vs) can be particularly useful at organic soil and peat sites. Recommendations for further work will be provided.