One of the more likely theories says that the name could be derived from the Proto-Slavic verb sadjati (modern Czech sázet, usazovat), meaning "to sediment", "to sink to the bottom".

[3] The longest tributaries of the Sázava are:[4] The most notable settlements on the river are the towns of Žďár nad Sázavou and Havlíčkův Brod.

After it crosses the border between the Vysočina and Central Bohemian regions, it flows past Vlastějovice, Horka II, Zruč nad Sázavou, Kácov, Tichonice, Soběšín, Český Šternberk, Rataje nad Sázavou, Ledečko, Samopše and Sázava (Benešov District).

From here it flows generally westward, past Stříbrná Skalice, Chocerady, Hvězdonice, Senohraby, Čtyřkoly, Čerčany, Poříčí nad Sázavou, Nespeky, Týnec nad Sázavou, Krhanice, Kamenný Přívoz, reaching its confluence with the Vltava (at the latter's 78.3 km mark) at the boundary between Hradištko and Davle, about 10 km (6 mi) south of the municipal border of Prague.

The most notable body of water directly on the Sázava is the Velké Dářko fish pond with an area of 206 ha (510 acres).