ABSTRACT Models for prediction of in-situ rock behaviour often suffer from lack of relevant input data, especially rock strength data. Rock mechanical testing of cores provides only discrete data points. This paper presents a method which produces a continuous plot of uniaxial compressive strength. The method is based on correlating standard log parameters with laboratory measured rock strength data. When a correlation has been established, it can be applied to new wells in the same field, giving a strength plot by computer processing of the necessary logs. The method has been applied to two wells in a North Sea field, resulting in a statistically significant correlation. Proper depth adjustments between core depth and log depth are essential. It is further important that the lithologies of interest are represented among the core material.