Recently, the USFDA issued the new 2018 guidance document for the industry on bioanalytical validation. Due to this occasion, it would be worthy to look back in time as well into the (near) future on potential practical impacts the 2018 guidance document might have on bioanalytical method validation and laboratory operations. Bioanalytical method development and validation is the most important part in regulated bioanalysis. Validated bioanalytical methods are used for the quantitative measurement of drugs and their metabolites, endogenous compounds, and biomarkers in biological fluids. Drug concentrations are indispensable for the evaluation and interpretation of pharmacokinetic (PK), toxicokinetic (TK), and bioequivalence (BE) study data. The bioanalytical methods are not only applied for quantification of small molecules (molecular weight ≤ 900 Da) but also for larger molecules such as proteins, antibodies, and peptides. Bioanalysis can be quite challenging due to the complexity of the biological sample matrix. In addition to the sample complexity, data quality obtained from analyzed samples is directly related to the bioanalytical method’s performance. Without any doubt, it is of utmost importance that bioanalytical methods used in bioanalysis have to provide reliable data.