Abstract: A computerized method and system for measuring and determining severity of illness of a neonatal ICU patient uses a computer and a software program to process measured parameter values from preselected physical conditions. Measurement ranges for each measured physical condition are divided into contiguous zones; the contiguous zones are given predetermined weighting factors using the software program. The software program, using user inputs, optimally selects a single value of each measured physical condition from several measurements. The single selected value of each parameter is then modified using the software program. In one embodiment, for achieving the modification, the software program provides a predetermined weighting factor depending on the parameter value selection. For each selected measured value, an applicable zone and its predetermined weighting factor is determined to generate a modified partial score representing each measured physical condition.