cdma2000 is a third generation wireless communications technology that provides seamless evolution from voice to high speed data and video through 3G1x, 1xEV-DO, and 1xEV-DV path, Integrating both voice and data services, 1xEV-DV supports packet data rates up to 3 Mbps. However, simultaneous operation of 3G1x and 1xEV-DV calls may degrade system capacity significantly as compared to operation of 3G1x calls alone. This paper presents analytical methodology in calculating interference for mixed 3G1x and 1xEV-DV calls made in the forward link. Monte Carlo simulations are performed to obtain capacity of the system. Results show that 3G1x system capacity is lowered by 2/3 and 1/3 at 0.1% and at 0.5% outage levels, respectively, when 3G1x and 1xEV-DV calls are simultaneously made.