Multipath routing is considered a promising technique to enhance multimedia transmission in wireless sensor networks, where the performance metrics such as reliability, security, and delivery ratio can be improved. On the other hand, tradeoff issues in designing multipath routing must be considered to exploit the advantages of multipath routings, such as energy consumption, delay, and packet overhead. This paper presents the effect of packet loss on reliability for video transmission in WMSN studied to investigate how multipath routing can enhance multimedia transmission. The results show that the reliability is affected based on the type of lost packets. Furthermore, based on the proposed model, the number of paths that achieve predefined reliability can be adjusted.