Introduction Development of children is a complex process that continues over a significant period of time of human life and a multitude of factors affect this process. Temperament is one such factor identified in literature and considered to be one of the most significant intra- personal factors influencing human functioning. 1,2 Temperament refers to traits displaying particular behavioural predispositions. These tendencies are relatively stable and biological in nature. One significant model of temperament defined it as individual differences in attentional, motor and emotional reactivity measured by recovery of response, intensity, latency and self-regulation processes like effortful control that modulate reactivity. 1 Temperament's basic biological processes can be shared across cultures but outcomes may vary depending on the child's experiences and cultural values3. Literature provides ample evidence that temperament co-determines typical and atypical functioning in humans. 1,3 This heightened the interest of clinicians and researchers to study the role of temperament in different developmental disabilities. Autism Spectrum disorder (ASD) is considered one of the most common developmental disabilities influencing the course of normal development in children and adolescents 4,5 with marked problems in social, communication and adaptive functioning. 6 According to a recent report of World Health Organisation (WHO), 7 ASD affects one child in every 160 children and the prevalence has increased globally in the past 15 years. 8 ASD is believed to have enormous social cost as it influences not only the life of sufferers, but also disrupt the functioning of a family and society in general. 9 Therefore, professionals become more interested in factors directly influencing the children with ASD. Many researchers have identified temperament as a variable significantly affecting the typical development along as well as course and prognosis of ASD. 10 Although researchers in western countries are studying temperament in varied populations, there is dearth of research in this particular area in Pakistan. Identifying the gap in knowledge related to temperament, the current study was planned as an attempt to provide some significant information regarding this pertinent area of functioning in the local context by assessing the pattern of temperament of ASD children to identify the temperament trait most prominent in this specific group and to explore gender differences in temperament profiles of the sample. J Pak Med Assoc 1437 RESEARCH ARTICLE Assessment of temperament in children with autism spectrum disorders Abia Nazim, 1 Ruhi Khalid 2 Abstract Objectives: To explore the temperament and its correlates in children with autism spectrum disorders. Method: The cross-sectional study was conducted in Lahore, Pakistan, from February 2015 to June 2016, and comprised children aged 5-11 years diagnosed with autism spectrum disorders selected from different institutes. A detailed demographic questionnaire, Temperament in Middle Childhood questionnaire and Childhood Behaviour questionnaire were administered through in-depth clinical interviews to collect information regarding temperament and significant demographic variables of the subjects. Results: Of the 92 subjects, there were 61(66%) boys and 31(34%) girls. Overall mean age was 8.62±1.87 years. The girls had relatively high scores on negative affectivity 19.54 ±5.14 (d=0.14) than boys. Whereas, boys scored comparatively higher on surgency 15.81±6.80 (d=0.21) and effortful control 13.69±3.72 (d=0.31) domains of temperament than girls. Negative affectivity shared significant inverse association with cognitive functioning r= - 0.35 (p=0.01). However, surgency r =0.17 and effortful control domains r =0.34 (p=0.01)were positively associated with intellectual functioning. Conclusion: Children with autism spectrum disorders showed a temperament profile different from children following typical development. Keywords: Temperament, Developmental disabilities, Autism spectrum disorder, Children, Individual differences. (JPMA 69: 1437; 2019). doi :10.5455/JPMA.290521 1 Forman Christian College University, Lahore, 2 Beaconhouse National University, Lahore. Correspondence: Abia Nazim. Email: abianazim@fccollege.edu.pk