Current procrastination measures fail to capture the multidimensional nature of procrastination behaviour and the multifaceted nature of procrastination problems, calling into question their use in evaluating procrastination in intervention research and clinical settings. Current measures also fail to differentiate procrastination from other forms of delay. These shortcomings have limited our theoretical understanding of delay in general and procrastination in particular. To address these problems, two sets of measures, the Multifaceted Measure of Academic Procrastination (MMAP) and the Delay Questionnaire (DQ), were developed in two parallel lines of multistage studies (N > 4000). In each line of research, a comprehensive approach to measurement development was followed to: (1) create items based on an initial theoretical model, (2) extensively evaluate the content of the definitions and items based on quantitative and qualitative data, (3) explore the factor structures and evaluate item functioning in order to reduce the number of items, and (4) confirm and refine the structure found in the exploratory analyses. The final structure of the MMAP consisted of four facets or separate scales: the Procrastination Behaviour Scale, the Negative Emotions Scale, the Perceived Negative Consequences Scale, and the Procrastination Duration Scale, which can be used separately or together. The final DQ consisted of six prototypes of delay: Irrational Delay/Anxious Procrastination, Hedonistic Delay/Hedonistic Procrastination, Inevitable Delay, Purposeful Delay, Arousal Delay, and Delay due to Emotional Problems. The extensive reliability analyses supported the reliability of the scales and subscales. Finally, after refining, establishing, and testing the new measures’ factor structures, the data from multiple surveys were gathered to provide evidence for the construct validity arguments for the new measures. Taken together, the findings support the validity of using various total scores including the severity of procrastination problems, duration of procrastination, procrastination behaviours measured by the MMAP, and prototypes and types of delay measured by the DQ. The validity studies also provided information regarding the prevalence of each form of delay and severe procrastination problems in student populations. The relations between procrastination and major personality factors, self-system variables as well as academic and health outcomes are discussed and compared with previous research findings.