The possibilities and limitations of the numerous individual methods used for boron analysis for BNCT in clinical and biological samples are reported in detail. The main interferences of the analytical methods are described. Sample pretreatment techniques are discussed. The methods reviewed for boron analysis for BNCT concern atomic spectrometry, radioanalytical methods, and imaging techniques. An error analysis of boron determinations in biomaterials is performed and typical boron distribution patterns in small mammalians are discussed.