Pyrazolines are well known and important nitrogen containing 5-membered heterocyclic compounds and various methods have been worked out for their synthesis. Numerous pyrazoline derivatives have been found to possess considerable biological activities, which stimulated the research activity in this field. They have several prominent effects, such as antimicrobial, antimycobacterial, antifungal, antiamoebic, anti-inflammatory, analgesic, antidepressant and anticancer activities. They also possess some potent receptor selective biological activity like Nitric oxide synthase (NOS) inhibitor and Cannabinoid CB1 receptor antagonists activity. 4,5-dihydro-1H- pyrazolines seem to be the most frequently studied pyrazoline type compounds. As a result, a large number of such pyrazolines using different synthetic methods for their preparation have been described in the chemistry literature. The present review provides an insight view to pyrazolines synthesis and its biological activities along with the compilation of recent patents on pyrazolines.