A panel of MSPs will decide tomorrow if our petition, signed by more than 20,000 people, should be closed.
Earlier this year the Scottish Government published its strategy for organ donation following a five-year review.
The Government said it would await the findings of the new opt-out system in Wales, which starts in 2015, before making a decision on whether to switch from the current opt-in system.
However campaigners including charity leaders have warned this delay will mean more patients waiting for transplant will die.
Labour MSP Mr Smith has written to the convenor of the Petitions Committee, David Stewart, urging him to keep the petition open while more information is gathered about the Welsh system.
He has called on Mr Stewart to invite the Welsh Health Minister to Scotland to discuss the change.
He said: "As a supporter of a change in the law to provide for a soft opt-out, rather than an opt-in, organ donation register, I was disappointed not to see a proposal for a bill in the Scottish Government's recently announced legislative programme.
"However, your Committee's consideration of this petition has, I believe, helped to raise awareness of the issues around organ donation in Scotland and the benefit which I, and many of the most expert groups in this field, believe would be achieved by a move to soft opt-out - namely an increase in the number of donations, and more lives saved.
"I am urging the Petitions Committee not to close the opt-out petition but instead to invite the Welsh Health Minister to Scotland to hear more about the change they have made and how we could make it in Scotland too.
"I was particularly struck by the evidence which your Committee obtained from BMA Scotland, in Helen Reilly's letter of December 2012, when she said: 'Surely if more could be done, it should be done,' and … I wonder if you would consider requesting some further evidence before ending your consideration of PE01453."
The MSP has pledged to make the case for a change in Scotland's transplant laws by pursuing a member's bill.
BMA Scotland has also said it will continue to support a campaign for an opt-out system.
Wales became the first part of the UK where people will be presumed to have consented for their organs to be donated unless they opt out.