Abstract: Seasonal occurrence of algae and physicochemical parameters of Samaru stream, Zaria (11°3`N; 7°42`E), Nigeria was investigated between the dry season (November/December 2003) and rainy season (May/June 2003). Five sampling stations were chosen along the stream length (within the university community) at approximately the same distances from one station to the other. Water temperature ranged from 19.5±1.05 and 29±0.67°C; pH 7.496±0.11 and 7.07±0.07; EC 328.1±63.92 and 364.5±75.37 μs cm-1, TDS 163.3±31.99 and 185.5±37.20 mg L-1; DO 6.046±0.51 and 4.03±0.49 mg L-1; NO3-N 1.37±0.17 and 5.32±0.90 mg L-1; PO4-P 136±53.07 and 42.3±4.74 mg L-1; BOD 0.89±0.22 and 0.32±0.07 mg L-1; transparency 0.00 and 0.36±0.06 m for dry and Rainy seasons respectively for the stream. Ten species of Bacillariophyta were observed in the dry season and 2 in the rainy season; 6 species of Cyanophyta in the dry season and 7 in the rainy season; 1 species of Euglenophyta in the dry season and none in the rainy season; 11 species of Chlorophyta were in the dry season and 7 in the rainy season and 3 species of Chrysophyta in the dry season and none in rainy season. Results from ANOVA showed significant difference for all parameters observed except pH between seasons.