A waste collection unit for collecting waste material through suction lines during a medical procedure, said unit comprising: a first waste container having a maximum storage volume and a connecting member configured for receiving a first suction line through which medical/surgical waste can be drawn into said first waste container; a second waste container having a maximum storage volume larger than said maximum storage volume of said first waste container; a vacuum circuit comprising a vacuum source adapted for providing a vacuum in said waste containers to draw the waste material into said waste containers through the suction lines; and a transfer valve disposed between said waste containers and operable between open and closed positions for allowing the transfer of waste material from said first waste container to said second waste container; wherein the second container comprises a connecting member configured for receiving a second suction line through which medical/surgical waste can be drawn into said second waste container; and the vacuum circuit is configured to provide independently controllable vacuum levels in the first and second waste containers (200, 202) such that first and second vacuum levels that are different from each other can be established in the first and second waste containers (200, 202), respectively; characterized in that the vacuum circuit comprises first and second vacuum regulators (408, 410) comprising first and second valve members (412, 418) and first and second valve actuators (414, 420) operatively coupled thereto to move the first and second valve members (412, 418) to selectively open fluid communication or air transfer between the first and second waste containers, respectively, and the vacuum source or between the first and second waste containers, respectively, and atmospheric pressure; and in that simultaneously, material can be drawn in to the first waste container at the first vacuum level and material can be drawn in to the second waste container at the second vacuum level, or one at a time into the first and second waste containers (200, 202). a first waste container having a maximum storage volume and a connecting member configured for receiving a first suction line through which medical/surgical waste can be drawn into said first waste container; a second waste container having a maximum storage volume larger than said maximum storage volume of said first waste container; a vacuum circuit comprising a vacuum source adapted for providing a vacuum in said waste containers to draw the waste material into said waste containers through the suction lines; and a transfer valve disposed between said waste containers and operable between open and closed positions for allowing the transfer of waste material from said first waste container to said second waste container; wherein the second container comprises a connecting member configured for receiving a second suction line through which medical/surgical waste can be drawn into said second waste container; and the vacuum circuit is configured to provide independently controllable vacuum levels in the first and second waste containers (200, 202) such that first and second vacuum levels that are different from each other can be established in the first and second waste containers (200, 202), respectively; the vacuum circuit comprises first and second vacuum regulators (408, 410) comprising first and second valve members (412, 418) and first and second valve actuators (414, 420) operatively coupled thereto to move the first and second valve members (412, 418) to selectively open fluid communication or air transfer between the first and second waste containers, respectively, and the vacuum source or between the first and second waste containers, respectively, and atmospheric pressure; simultaneously, material can be drawn in to the first waste container at the first vacuum level and material can be drawn in to the second waste container at the second vacuum level, or one at a time into the first and second waste containers (200, 202).