This chapter provides an overview of some of the factors related to growth and development of newborn. Failure to thrive (FTT) is defined as inadequate physical growth diagnosed by observing growth over time using a standard growth chart such as the WHO growth chart. A downward change in growth that has crossed two major growth percentiles in a short time is also suggestive of FTT. If a child less than 6 months old has not grown for two consecutive months or a child older than 6 months has not grown for three consecutive months, it indicates FTT. Some of the causes of failure to thrive include prematurity with its complications, infections, chromosomal abnormalities, malabsorption syndromes, vitamins and mineral deficiencies, hyperthyroidism, chronic anemia, renal tubular acidosis etc. Weight, height or length, head circumference and midupper arm circumference must be measured accurately. Developmental delay is suspected if child exhibits a significant delay in the acquisition of milestones or skills, in one or more domains of development. Significant delay has been traditionally defined as discrepancy of 25% or more from the expected rate, or a discrepancy of 1. 5–2 standard deviations from the normal. Global developmental delay is defined as a delay in two or more developmental domains. Global developmental delay can be the presenting feature of a huge number of neurodevelopmental disorders. Parents\' evaluation of developmental status (PEDS) is a parent interview form that provides an algorithm to guide a need for referral, more screening, or continued surveillance. Chromosome analysis yields the highest number of abnormalities when investigating global developmental delay, even where there are no clinical features of a genetic problem. Thyroid function tests (TFT) are easy to perform and should be done as a first-line investigation for developmental delay. Trivandrum Development Screening Chart is a simple developmental screening test for babies below 6 years that can be used in large scale community developmental screening programs by Anganwadi workers and other health workers.