The ejaculation and mounting times of a stallion, as well as the amount of time it takes for the stallion to respond to an oestrus mare, are all elements that might affect the libido of the horse. In order to gain an understanding of how tropical horses adapt to potentially difficult climatic circumstances in terms of their sexual performance, it is necessary to study their reproductive behaviour. The present investigation was carried out on six healthy Marwari stallions (aged between 50 to 140 months) to evaluate and to analyse their sexual behaviour during the breeding season in the arid region. The study was carried out for a period of three weeks and sexual behaviour parameters were recorded at the time of semen collection. Parameters observed and analysed in the present study include erection time, reaction time, ejaculation time, number of mounts and number of thrusts. Erection time, reaction time and ejaculation time of stallions was 19.02±1.18 sec, 29.11±1.37 sec, 26.86±0.95 sec, respectively. The number of mounts and number of thrusts of stallions was 1.39±0.09 and 10.00±0.17 respectively. The above study describes the normal sexual behaviour parameters of Marwari stallions in the arid region and analysed that non-significant (P>0.05) difference exists among the horses for various sexual behaviour parameters.