Disclosed herein is a technique for preventing words from spanning across message blocks of a short message service (SMS) message. An SMS message is generated at a source wireless device, and an SMS manager, executing on the source wireless device, determines whether any words in the SMS message span across two or more message blocks of the SMS message. When so determined, the SMS manager attempts to shift characters of the SMS message across the message blocks to eliminate any word spanning. When the attempt to shift the characters between message blocks requires at least one additional message block to transmit the complete SMS message, the SMS manager gathers information about the destination wireless device to determine whether it is necessary to carry out the aforementioned shifting prior to sending the message blocks. The SMS manager then transmits the message blocks either unmodified or modified (i.e., shifted).