The breeding sites of Culex quinquefasciatus (Say) was investigated with seasonal prevalence during 2012-2013 in south west region of Puducherry. The study revealed the density of vector immature of L3 stage was dominant during pre monsoon and post monsoon seasons (420 and 390 individuals). The significant high numbers was due to the onset of monsoon rains available in the gutters, tree holes followed by earthen pots. Few numbers were identified in plastic bottles, coconut shells and tyres. The container-type breeding sites yielded approximately 1455 individuals in gutter and 1050 in tyres. The results indicate that Culex quinquefasciatus had invaded almost all different types of containers and significant (p<0.05) during post and pre monsoon seasons and non-significant during summer and monsoon. The present study highlights that Cx. quinquefasciatus had invaded urban areas of south west region of Puducherry with seasonal prevalence. The results also indicate the needs for studies locally, prior to larviciding.