Palghar was part of Thane district. After struggle and demand for 20 years new district approved by cabinet of Maharashtra.
The district is the northernmost part of the Konkan lowlands of Maharashtra. It comprises the wide amphitheater like Ulhas basin on the south and hilly Vaitarna valley on the north together with plateaus and the slopes of Sahyadri. From the steep slopes of the Sahyadri in the east, the land falls through a succession of plateaus in the north and center of the district to the Ulhas valley in the south.
The main river flowing through the district is Vaitarna. The river has many tributaries; two important of them (within the boundaries of this district) are Barvi and Bhatsa. Vaitarna, the largest of Konkan Rivers rises in the Tryambak hills in Nashik district, opposite to the source of Godavari, The river flows across Shahapur, Vada and Palghar talukas and enter the Arabian Sea through a wide estuary off Arnala. Vaitarna River is 154 km long and has a drainage area that practically covers the entire northern part of the district. It has a number of tributaries; the most important of them are Pinjal, Surya, Daherja and Tansa. Ulhas river which flows to Arabian see is Vasai creek, districts southern border. Arnala Island is located in Vasai taluka, at the entrance to the Vaitarna estuary.